Analysis Guide 180 Enu

Tekla StructuresAnalysis Guide

Product version 18.0

February 2012

2012 Tekla Corporation

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Contents

4

Conventions used in this guide ..............................................................................................................3

1 Getting Started with Analysis....................................................................... 7

1.1 Basics...................................................................................................................................... 7Carrying out structural analysis .............................................................................................................. 10Members, bars and area objects.............................................................................................................. 10Nodes and rigid links .................................................................................................................................. 11

1.2 Determining member properties........................................................................................ 12Member analysis class................................................................................................................................ 13Support conditions ...................................................................................................................................... 14Defining support conditions ..................................................................................................................... 15Support condition symbols ....................................................................................................................... 16Analyzing composite beams ..................................................................................................................... 18

Viewing analysis results ..................................................................................................................... 18Manual method - limitations ........................................................................................................... 19

Design information...................................................................................................................................... 19Member position.......................................................................................................................................... 20Analysis member offsets............................................................................................................................ 21Analysis properties of components......................................................................................................... 22Analysis properties of slab components................................................................................................ 23Properties of intermediate members...................................................................................................... 24Defining buckling lengths (columns) ..................................................................................................... 24

Effective buckling length ................................................................................................................... 25Kmode options ...................................................................................................................................... 25

1.3 Analysis information and settings..................................................................................... 26A closer look at the analysis model........................................................................................................ 26

Objects ..................................................................................................................................................... 27Nodes connecting members and elements ................................................................................... 27

Loads in analysis .......................................................................................................................................... 28Load modeling code .................................................................................................................................... 29Analysis method........................................................................................................................................... 30

1.4 Additional information resources...................................................................................... 30

Contents

5

2 Loads.............................................................................................................. 33

2.1 Basics.................................................................................................................................... 33Automatic loads and load groups ........................................................................................................... 34

2.2 Grouping loads .................................................................................................................... 34Load group properties................................................................................................................................. 34Load group compatibility........................................................................................................................... 35Working with load groups......................................................................................................................... 36

Checking loads and load groups ...................................................................................................... 36Changing the load group ................................................................................................................... 37Importing and exporting load groups ............................................................................................ 37

2.3 Load types and properties .................................................................................................. 37Load types ...................................................................................................................................................... 38Load forms ..................................................................................................................................................... 39Load magnitude............................................................................................................................................ 40Temperature loads and strain................................................................................................................... 41

2.4 Distributing loads................................................................................................................ 41Attaching loads to parts or locations .................................................................................................... 41Applying loads to parts .............................................................................................................................. 42Loaded length or area................................................................................................................................. 43Modifying load distribution ...................................................................................................................... 43

2.5 Working with loads............................................................................................................. 44Changing loaded length or area.............................................................................................................. 45Scaling loads in model views ................................................................................................................... 45Defining varying wind loads ..................................................................................................................... 46

2.6 Load reference..................................................................................................................... 47Load Groups... .............................................................................................................................................. 47Create Point Load ........................................................................................................................................ 49Create Line Load........................................................................................................................................... 50Create Area Load.......................................................................................................................................... 51Create Uniform Load................................................................................................................................... 53Create Temperature Load .......................................................................................................................... 54Create Wind Load ........................................................................................................................................ 55

Contents

6

3 Analysis and Design...................................................................................... 57

3.1 Analysis part properties...................................................................................................... 573.2 Analysis model properties .................................................................................................. 62

Objects in an analysis model.................................................................................................................... 62Analysis model filter ............................................................................................................................ 64

Member axis.................................................................................................................................................. 64Member end connectivity.......................................................................................................................... 65Model merging with analysis applications........................................................................................... 65Analysis method........................................................................................................................................... 65Seismic analysis ........................................................................................................................................... 66Modal analysis.............................................................................................................................................. 67Design codes and methods ....................................................................................................................... 68

Design properties ................................................................................................................................. 68Contents of STAAD.Pro results files and reports................................................................................. 68

3.3 Load combination ............................................................................................................... 69Load combination properties.................................................................................................................... 69Load combination factors.......................................................................................................................... 69Load combination types............................................................................................................................. 70Creating load combinations...................................................................................................................... 72Automatic load combination.................................................................................................................... 73Automatically including loads in combinations ................................................................................. 74Manual load combination ......................................................................................................................... 74

3.4 Working with analysis and design models........................................................................ 75Checking objects contained in an analysis model.............................................................................. 75Changing model creation method .......................................................................................................... 75Adding or removing analysis objects ..................................................................................................... 76Viewing analysis results............................................................................................................................. 76Exporting an analysis model..................................................................................................................... 77Copying an analysis model........................................................................................................................ 77Copying an analysis part ........................................................................................................................... 77

3.5 Analysis and design reference ........................................................................................... 78Analysis > Analysis & Design Models... ................................................................................................. 78Create Node................................................................................................................................................... 80Create Rigid Link.......................................................................................................................................... 80Merge Selected Nodes................................................................................................................................ 81New.................................................................................................................................................................. 82

Creating analysis model rules ........................................................................................................... 85Add selected objects ................................................................................................................................... 86Remove selected objects ........................................................................................................................... 87Load combinations... ................................................................................................................................... 87Get results...................................................................................................................................................... 88Reset Editing Of Selected Parts ............................................................................................................... 88

BasicsGetting Started with Analysis 7

1 Getting Started with Analysis

Introduction This chapter explains how to prepare a Tekla Structures model for structural analysis and design. It includes a general description of the principles of analysis and design and discusses the theoretical basis of the analysis method used in Tekla Structures. This chapter also explains what is included in the analysis model, and how it is included. You will also learn how to define support conditions for parts.

Audience This chapter is for engineers and designers who run structural analysis on concrete and steel structures.

Assumedbackground

We assume that you have created parts.

Contents This chapter is divided into the following sections:

Basics (7) Determining member properties (12) Analysis information and settings (26)

1.1 Basics

In this section This section presents the basic vocabulary and concepts we use to describe structural analysis in Tekla Structures. The illustrations below show the analysis concepts and procedures.


Physical model A physical model includes the parts you have created in the model, and information related to them. Each part in the physical model exists in the completed structure.

Load model The load model contains information about loads and load groups. It also contains information about the building code Tekla Structures uses in load combination. To create a load model, see Loads (33).

Analysis model An analysis model is used when structural analysis is run.Tekla Structures generates the required analysis members automatically for the physical model parts when you have an analysis model selected in the Analysis & Design models dialog box. The following analysis objects are generated:

Nodes and analysis members and elements of the physical parts Support conditions for nodes Connectivity between the members and nodes Loads to members and elementsThe analysis model also includes load combinations.

Analysisapplication

Tekla Structures links with a number of analysis applications and also supports export with them in several formats. The analysis application you use to run structural analysis uses data from the analysis model to generate analysis results.

For more information on the analysis applications that you can use with Tekla Structures, visit Tekla Extranet at https://extranet.tekla.com. You can also access Tekla Extranet from Tekla Structures at Help > Online Support > Tekla Extranet.

Topics Carrying out structural analysis (10)

Members, bars and area objects (10)

Nodes and rigid links (11)

Parts

Loads

Node

Analysis bar and member

Analysis model

Physical and load models

Tekla Structures analyzes parts using properties in the profile and material catalogs, including user-defined properties. If there are no profile or analysis properties in the catalog, Tekla Structures calculates them using the profile dimensions in the model.


Carrying out structural analysisTo carry out structural analysis in Tekla Structures:

1. Create the main load-bearing parts to form the physical model. See About parts. There is no need to detail or create connections at this stage.

2. Create the load model. See Loads (33).3. Create a new analysis model and define its properties. See Analysis model properties (62) and

New... (82). The analysis parts are created automatically for the analysis model.4. Set the support conditions for parts and connections, as well as other analysis properties for

individual members. See Determining member properties (12).5. Create load combinations. See Load combinations... (87).6. Check the analysis model in a Tekla Structures model view. See Checking objects contained in

an analysis model (75).7. Check the analysis parts and modify their properties if needed.

Now you are ready to run the analysis by exporting the analysis model. See Exporting an analysis model (77).

See also The following sections discuss the theoretical basis of the analysis method used in Tekla Structures. They also explain what is included in the analysis model, and how it is included.

Members, bars and area objects (10) A closer look at the analysis model (26) Loads in analysis (28) Load modeling code (29) Analysis method (30)

Members, bars and area objectsEvery physical part that you select to include in the analysis model is represented by an analysis part, containing various analysis properties.

Frame objects (beams, columns, bracings) consist of one or more bars, and each bar object consists of one or more members. Specifically, a bar consists of one or more members which lie along the same line. In the most typical case, an analysis part consists of one bar, and one or more members if split positions need to be created on the bar. Split positions are created to create proper connectivity with intersections with other parts. An analysis part contains more than one bar if it is a polybeam, or if it is tapered in a way that members do not lie on the same line.

Some analysis engines work on members whereas others work on bars. This affects also the drawing of the analysis model. Either member or bar numbers are drawn in the view.

Slabs and walls are modeled as area objects. When transferred to the analysis engine, meshing creates the individual elements of the area object.

See also Determining member properties (12)

To create accurate analysis models, make sure that connected parts have common handles, for example, at grid line intersections.


Nodes and rigid links

Nodes Nodes connect analysis members and elements. Tekla Structures creates nodes at:

The ends of members The intersection points of member axes The corners of elementsThe following properties affect the exact location of nodes:

Part profiles, i.e. neutral axis and orientation Part reference lines (see Part handles) Location of member axes (see Member position (20) and Member axis (64)) Location and shape of elementsTo force members to meet in the analysis model, Tekla Structures may need to merge nodes, shift or extend member axes, create rigid links between nodes, ignore minor members, etc.

You can create additional nodes when needed. Sometimes, intermediate nodes are needed along a member, for example, in frequency analysis.

For more information on where and how Tekla Structures creates nodes, members, and elements, see A closer look at the analysis model (26).

Rigid links Rigid links are links between nodes that do not permit relative motion between them.

Rigid links have the following properties in the analysis model:

Profile = PL300.0*300.0 Material = RigidlinkMaterial Density = 0.0 Modulus of elasticity = 100*109 N/m2

Poissons ratio = 0.30 Thermal dilatation coefficient = 0.0 1/K

See also Create Node (80)

Create Rigid Link (80)

The methods used to create a physical model affect the analysis model. Because of this, you may need to try different modeling methods and analysis model properties in order to create an accurate analysis model of a complex physical model.

The analysis engine may model rigid links by dedicated rigid link objects.

Determining member propertiesGetting Started with Analysis 12

1.2 Determining member propertiesYou can define analysis properties for individual parts, or for an entire analysis model. This section describes the properties of the individual analysis members. To define these, use the Analysis, Start releases, End releases, Composite, Spanning, Loading, Design, Position, Bar Attributes and Area Attributes tabs in the analysis part properties dialog boxes, or the Analysis tab in the connection and detail dialog boxes.

To display the analysis part properties dialog box, select the part and click Analysis > Analysis Part Properties.

For more information on using common properties for the parts in an analysis model, see Analysis model properties (62).

Topics Member analysis class (13)

Member position (20)

Analysis member offsets (21)

Analysis properties of components (22)

Analysis properties of slab components (23)

Analyzing composite beams (18)

Support conditions (14)

Defining support conditions (15)

Design information (19)

You can set analysis properties for parts before creating an analysis model. The analysis properties are applied when the parts are added in an analysis model.


Properties of intermediate members (24)

Defining buckling lengths (columns) (24)

Member analysis classUse the Analysis tab in the analysis part properties dialog boxes to define how Tekla Structures handles individual members in the analysis. The following table lists the options in the Class list.

Tekla Structures shows the member analysis class of parts using different colors in the analysis model. The Color column lists these colors.

Option Description Color

Beam Line object of two nodes.

Member can take any load, including temperature.

Dark red

Column Vertical line object of two nodes. Modeled from bottom to top.


Dark red

Secondary Line object of two nodes.


Members that are classified as SecondaryKeep axis position always is off by default and secondary parts snap to nearest nodes instead of part end nodes.

Dark red

Wall Polygon object of three or more nodes.

For rectangular concrete panels and concrete slabs using design codes ACI and BS 8110 only.

Tekla Structures analyzes the concrete panel or slab as a shear wall that does not take any direct loads.

Aqua

Slab Polygon object of three or more nodes.


Aqua

The options above combined with one of the following:

Truss Member can only take axial forces, not bending or torsion moments, or shear forces. Usually used for brace members.

Green

Truss - Tension only

Member can only take tensile axial forces, not moments or shear forces. If this member goes into compression, it is ignored in the analysis.

Pink

Truss - Compression only

Member can only take compressive axial forces, not moments or shear forces. If this member goes into tension, it is ignored in the analysis.

Yellow

Ignore Member ignored in the analysis.

Self weight load is taken into account, if you have set the Generate self weight load to Yes on the Loading tab.

Member is not shown in the model.

Shell Member can take any load, except temperature. Use to analyze slabs, panels, and plates.

Aqua


For more information on members with the Truss, Tension only, or Compression only setting, see A closer look at the analysis model (26).

To indicate the member analysis class of parts in an object group using colors:

1. Click View > Representation > Object Representation....2. Select the object group.3. In the Color column, select Color by analysis type.4. Click Modify.

For more information on object representation and object groups, see Object representation settings and Object groups.


Support conditionsIn structural analysis, the stresses and deflections of a part depend on how it is supported by, or connected to, other parts. You normally use restraints or springs to model connections. These determine how analysis members move, deflect, warp, deform, etc., in relation to each other, or to nodes.

Member ends and nodes have degrees of freedom (DOF) in three directions. The displacement of a member end can be free or fixed, and the rotation can be pinned or fixed. If the degree of connectivity is between free, or pinned, and fixed, use springs with different elastic constants to model them.

Tekla Structures uses part, connection, or detail properties to determine how to connect members in the analysis model. To define the member end conditions, use the Start releases and End releases tabs in the analysis part properties dialog boxes. The connection and detail dialog boxes have Analysis tabs.

The analysis properties of a member determine the degrees of freedom for each end of a main part or member. The first end of a part has a yellow handle, the second end has a magenta handle. See also Part handles.

See also Defining support conditions (15)

Rigid diaphragm Only applies to contour plates and concrete slabs parallel to the global xy plane.

Nodes that belong to a part matching the filter will be connected with rigid links which together affect displacement. For example, you can use column_filter to connect only column nodes to rigid diaphragms.

Lilac

Plate Same as Shell but plate, membrane, or mat foundation elements are used in the analysis application.

Aqua

Membrane Aqua

Mat foundation Aqua

The analysis application that you use may not support all options.

Option Description Color


Determining member properties (12)

Defining support conditions

Parts Use the Start releases and End releases tabs in the analysis part properties dialog boxes to define support conditions. The Start releases tab relates to the first part end (yellow handle), the End releases tab to the second part end (magenta handle).

Plates To define the support conditions of contour plates, concrete slabs, and concrete panels, use the Supported list box on the Area attributes tab in the analysis part properties dialog box.

Connections anddetails

Use the Analysis tab in the connection or detail dialog boxes to define the support conditions for the members and node in a connection. Use the Member selection list box to associate the support conditions with each connection part (Primary, 1. secondary, 2. secondary, etc.).

Supportconditions

Tekla Structures includes four predefined combinations for member ends, and an option for user-defined settings. The predefined combinations (the first four in the following table) automatically set the appropriate support conditions and degrees of freedom. The combinations are:

The support conditions of a member end can be:

CombinationSupport condition

Translational DOFs Rotational DOFs

Supported Fixed Fixed

Supported Fixed Pinned

Connected Fixed Fixed

Connected Fixed Pinned

Use this option to define your own settings for the supports and connections at member ends. You can use springs and almost any combination of degrees of freedom.

To ensure that the part remains stable, and that all loads applied to it pass through to the other structures, avoid using combinations with too many degrees of freedom.


Displacementsand rotations

U denotes translational degrees of freedom (displacement). R denotes rotational degrees of freedom (rotation). Define the degrees of freedom in the global coordinate system. The options are:

See also Support conditions (14)

Determining member properties (12)

Analysis part properties (57)

Support condition symbolsTekla Structures displays symbols for nodes that indicate the support conditions of a node.

Option Description

Connected Member end is connected to an intermediate analysis node (another part).

Indicate degrees of freedom for the node.

Supported Member end is the ultimate support for a superstructure (for example, the foot of a column in a frame).

Indicate degrees of freedom for the support.

Option More information

Free Only applies to translational degrees of freedom.

Pinned Only applies to rotational degrees of freedom.

Fixed

Spring Enter translational and rotational spring constants. The units Tekla Structures uses depend on the programs unit settings.

Partial release Only applies to rotational degrees of freedom.

Use to specify the degree of connectivity, if it is between fixed and pinned. Enter a value between 0 (fixed) and 1 (pinned).


Symbol Support condition

No supports

Pinned connection

Fixed connection

Translational direction fixed

Translational direction spring


See also Support conditions (14)

Defining support conditions (15)

Analyzing composite beamsComposite beams consist of a beam and studs, with a concrete slab on top of the beam. You can define the analysis properties of the slabs in composite beams, and define the width of the slab manually or automatically.

To define the properties of the concrete slab in a composite beam:

1. Open the Beam Analysis Properties dialog box and go to the Composite tab.2. Select the Composite beam option in the Composite beam list.3. Select a Material and enter the Thickness of the slab.4. To define the effective slab width:

Manual method: Select the To the left from the beam and/or To the right of the beam option button and enter a value in the field next to these buttons. See also Manual method - limitations (19).

Automatic method: For the left and right side, select the Automatic, half of span length divided by option button and enter a value in the field next to these buttons. When you run the analysis, Tekla Structures calculates the effective slab width by dividing the span length of the beam by the value you enter.

See also Viewing analysis results (18)

Viewing analysis resultsTo view the analysis results for composite beams, right-click the beam and select Inquire on the pop-up menu. The analysis results include:

Element and node IDs Effective width Slab thickness Slab material Concrete strength Rib width and height

Rotational fixed

Rotational spring

Symbol Support condition


Stud diameter and length

Manual method - limitations Effective width cannot exceed the distance to the nearest beam. Effective width cannot be more than half the distance to the nearest composite beam. If there is no beam on either side of the composite beam, the slab width is zero. Use the

Automatic composite beam option to have Tekla Structures calculate the slab width.

Design informationUse the Design tab in the part properties dialog boxes to view and modify the design properties of individual parts in an analysis model. Design properties are properties which can vary, according to the design code and the material of the main part (for example, design settings, factors, and limits).

The properties you see when you first open the dialog box are the properties that apply to the entire analysis model you have selected in the Analysis & Design Models dialog box. See also Design codes and methods (68).

To set different design properties for specific parts, modify the values in the appropriate analysis part properties dialog box.

For example, if the analysis model contains parts with different material grades, define the most common material grade using the analysis model properties. Then change the material grade of specific parts using the appropriate analysis part properties dialog box.

To omit individual members from the design check when you run the analysis, set the following properties to No:

Steel parts: Check design - Enable design check of member Concrete parts: Calculate required area - Enable design check of member



Defining buckling lengths (columns) (24)

Effective buckling length (25)

Kmode options (25)

Member position

Location ofmember axes

The locations of the member axes of parts define where the analysis members actually meet, and their length in the analysis model. They also affect where Tekla Structures creates nodes. See Members, bars and area objects (10) and A closer look at the analysis model (26).

Use the options in the Axis list on the Position tab in the analysis part properties dialog boxes to define the member axis location of individual parts for analysis purposes. The options are:

Tekla Structures uses the options above for each part when you select the Model default option for the member axis location in the analysis model properties. See New... (82) and Member axis (64).

Keeping axisposition

Use the options in the Keep axis position list to define whether the axis position is changed according to changes in the physical model. The options are:

Option Description

Neutral axis The neutral axis is the member axis for this part. The location of the member axis changes if the profile of the part changes.

Reference axis The part reference line is the member axis for this part. See also Part handles.

Reference axis (eccentricity by neutral axis)

The part reference line is the member axis for this part. The location of the neutral axis defines axis eccentricity.

Top plane The member axis is bound to the top plane.

Middle plane The member axis is bound to the middle plane.

Bottom plane The member axis is bound to the bottom plane.

Left plane The member axis is bound to the left plane.

Right plane The member axis is bound to the right plane.

Middle plane (of left/right)

The member axis is bound to the middle plane of left/right.

If you select the Neutral axis option, Tekla Structures takes the part location and end offsets into account when it creates nodes. See End offsets. If you select either of the Reference axis options, Tekla Structures creates nodes at part handles.


Connectivity Use the Connectivity options to define the snapping conditions.

Bound memberlocation

Use the options in Axis modifier X, Y and Z to define whether the member location is bound to global coordinates, grid line or neither. The options are:

Offset Use the Offset X, Y and Z boxes to define the member location in global coordinates.

Use the options in the Longitudinal offset mode list to define if the part end offsets of the physical part are considered when Tekla Structures creates the analysis part. For more information see Analysis part properties (57).


Analysis member offsetsUse offsets at the ends of analysis members to shorten or lengthen members in their local x directions, for analysis purposes and to take the eccentricity effects into account.

Option Description

No The axis is free to move when snapping end positions to nearby objects. Use this option for secondary members.

Partial - keep in major direction

The axis is free to move partially, but the member is not moved in major direction.

Partial - keep in minor direction

The axis is free to move partially, but the member is not moved in minor direction.

Yes The axis are not moved, but end positions can move along axis (thus extending or shortening the member).

Yes - Keep end positions also

The axis and the end positions of the member are not changed.

Option Description

Automatic The member snaps or connects with rigid links to other members.

Manual The member does not snap or connect with rigid links to other members. Automatic connectivity to other members is created only if the member position matches exactly the other member.

Option Description

None The member location is not bound.

Fixed coordinate The member location is bound to the coordinate you enter in the X, Y or Z box.

Nearest grid The member is bound to the nearest grid line (the snap zone is 1000 mm).


For example, if a beam only actually spans the clear distance between two supporting columns, you can use offsets to only include the clear distance in the analysis, instead of the distance between the center points of the columns.

Another example is an eccentric connection between a precast concrete column and beam. To take the eccentricity of the load from the beam into account, use the analysis offsets of the beam.

Use the Bar attributes tab in the analysis part properties or connection dialog boxes to define the offset at each end of a member. For more information, see Analysis part properties (57).


Analysis part properties (57)

Analysis properties of componentsUse the Analysis tab in the connection or detail dialog boxes to define how Tekla Structures handles connections and details in the analysis.

The analysis properties of connections and details are:



Analysis properties of slab componentsUse the Analysis tab in the Slab generation with polygon plate (61) and Slab generation with points (62) dialog boxes to define the analysis properties of parts created using these components.

The following table lists the analysis properties of slab components. The option you select in the Analysis type list box limits the other properties you can define (see the Only use for column).

Property Description

Use analysis restraints

Set to Yes to use the analysis properties of the connection or detail in the analysis, instead of the analysis properties of the parts in the connection.

You must also select Yes in the Member end release method by connection list box in the Analysis Model Properties dialog box when you create the analysis model. See Member end connectivity (65).

Member selection Use to associate the analysis properties with each connection part (Primary, 1. secondary, 2. secondary, etc.).

Restraint combination

See Support conditions (14) and Defining support conditions (15).

Support condition

Longitudinal member offset

See Analysis member offsets (21).

Analysis profile Tekla Structures uses this profile in the analysis, instead of the one in the physical model, in order to take the stiffness of the connection or detail into account.

Analysis profile length

This means that in the analysis, Tekla Structures overrides the profile of the part in the physical model, for this length.

Property Description Only use for

Analysis type How Tekla Structures analyzes the slabs.

Ignore: Slabs are not analyzed. Beam: Analyze each slab as a beam. Plate: Analyze each slab as a plate. Rigid diaphragm: Analyze slabs as a

rigid diaphragm.

See also Member analysis class (13).

Beam axis The location of the beam axis. See also Member position (20).

Beam


Properties of intermediate membersWhen creating an analysis model, Tekla Structures may need to produce more than one analysis member for each physical part. This can result in intermediate members and member ends.

Tekla Structures determines the analysis properties of intermediate members as follows:

1. The member analysis type and member axis location of the analysis members are the same as of the original part.

2. The analysis offsets of the part ends apply to the corresponding analysis member ends. Intermediate member ends do not have analysis offsets.

3. The support conditions of all intermediate member ends are Connected. The translational and rotational degrees of freedom are all Fixed. This reflects the nature of the physical part, which is a continuous length.

4. The effective buckling length of each analysis member is K*L. K is the length factor for buckling. L is length, a value described by the Kmode design property. For more information, see Defining buckling lengths (columns) (24).

5. The other design properties are the same for the analysis members as for the original part.


Defining buckling lengths (columns)Tekla Structures allows you to define buckling lengths for column segments, which represent the building levels. Tekla Structures automatically divides columns into segments at the point where a support in the buckling direction exists, or where the column profile changes.

See also Effective buckling length (25)

Kmode options (25)

Restraints The support conditions of beam ends. The options are Pinned and Fixed.

Beam

Plate plane The plane on which to create the elements and nodes. If you select Top plane, Tekla Structures creates the elements on the top surface of the slab.

Plate

Element type The shape of the elements. Plate

Element size x and y: The approximate dimensions of the elements, in the local x and y direction of the slab. For triangular elements, the approximate dimensions of the bounding box around each element.

Holes: The approximate size of the elements around openings.

Plate

Filter Nodes that belong to a part matching the filter will be connected to the rigid diaphragm. For example, you can use column_filter to connect only column nodes to rigid diaphragms.

Rigid diaphragm

Property Description Only use for


Effective buckling lengthEffective buckling length is K*L, where K is the length factor and L is the buckling length. To calculate a parts effective buckling length:

1. Open the analysis part properties dialog box and go to the Design tab.2. Select an option for Kmode. For more information about the available options, see Kmode

options (25).3. Enter one or more values in the K - Length factor for buckling field. The number of values you

can enter depends on the option you selected in the Kmode field. For multiple values: Enter a value for each column segment starting with the lowest segment, and Use spaces to separate multiple values:

You can also use multiplication to repeat factors, for example, 3*2.00.4. Go to the L - Buckling length field:

To automatically calculate length values, leave the fields blank. To override one or more length values, enter values in the relevant buckling length fields.

The number of values you need to enter depends on the option you selected in the Kmode field. You can use multiplication to repeat buckling lengths, for example, 3*4000.

5. Create the analysis model and use the Tools > Inquire > Object command on a part. The Inquire Object dialog box opens and displays the member number and the effective buckling length for each segment:

Kmode optionsUse the Kmode options to define how Tekla Structures calculates buckling lengths. The options are:

Option Description

Physical member L is the length of the column.

Column segment L is the length of one column segment.

Analysis information and settingsGetting Started with Analysis 26

1.3 Analysis information and settingsThis section generally discusses the analysis process and describes analysis settings.

Topics A closer look at the analysis model (26)

Loads in analysis (28)

Load modeling code (29)

Analysis method (30)

A closer look at the analysis modelThis section gives detailed information on how Tekla Structures creates analysis models of physical models.

Column segment, multiple values

L is the length of one column segment with user-defined factors and lengths for each column segment.

Analytical member L is the length of the member in the analysis model.

Analytical member, multiple values

L is the length of the member in the analysis model with user-defined factors and lengths for each member.

Option Description

The methods used to create a physical model affect the analysis model. Because of this, you may need to try different modeling methods and analysis model properties in order to create an accurate analysis model of a complex physical model.


See also Objects (27)

Nodes connecting members and elements (27)

ObjectsTekla Structures ignores the following objects in the analysis, even if you have included them in the analysis model (see Objects in an analysis model (62)):

Parts and loads that are filtered out (see Analysis model filter (64)) Component objects (minor parts, bolts, reinforcing bars, etc.) Parts with the Ignore setting (see Member analysis class (13))

Truss members Tekla Structures does not split members with the Truss, Tension only, or Compression only setting (truss members) when two or more truss members intersect with a normal member or with another truss member.

Nodes connecting members and elementsTekla Structures first creates analysis nodes:

On member axes at the ends of parts At the intersection points of member axes At the corners of elementsTekla Structures then checks if the analysis members have common nodes.

Tekla Structures creates common nodes for members if a connection exists between the members.

Element nodes This is how Tekla Structures creates nodes when plates connect with other parts:

Node colors The color of the node shows the status of the connectivity of the node and whether the node has been selected.

Connected part Action

Beam Tekla Structures splits the beam and creates nodes in it at the element corners.

Column Tekla Structures creates a node at the column.

Another plate Tekla Structures creates the analysis elements so that the plates have common nodes on the edges of the plates.

Node colorConnectivity status Selection Example

Magenta Disconnected Selected


Loads in analysisThese are the principles that Tekla Structures follows when it processes loads in the physical model to create analysis model loads.

You define which loads are included in the analysis model. Tekla Structures applies these loads to members and elements, based on each loads part name or selection filtering criteria, bounding box, and load panel properties. See Applying loads to parts (42) and Modifying load distribution (43).

In load decomposition, the parts to which a load is applied are projected to the load plane. The load is then applied to these parts according to the load panel properties, of which the loads spanning properties and distance from each part are most important.

Point loads A point load is applied to the nearest node, or member or element location. If the point load is not located directly on any of these, it may either snap to the nearest location or it may be split into several loads, depending on the filtering criteria, bounding box, and load panel properties.

Line loads A line load is transferred to members and elements that are inside the bounding box of the line load, and that match the part name or selection filtering criteria of the load. In special cases the line load may be decomposed to point loads if it is not perpendicular to the part it is applied to. If several members receive the load, the load is distributed based on the length of each member and the distance between the load and member.

Area and uniformloads

Area loads are decomposed to line loads, and in special cases to point loads if they are not perpendicular to the part they are applied to. These decomposed loads are then applied to members and elements. Members inside the bounding box of the load and that match the part name or selection filtering criteria receive the load. Load panel properties, especially single or double spanning and spanning direction, also affect load decomposition.

Nodal load Tekla Structures binds loads to nodes or members in the analysis model. A load is a nodal load if:

Magenta Disconnected Not selected

Green Connected Selected

Green Connected Not selected

Node colorConnectivity status Selection Example


It is between two nodes and the distance to the nearest node is less than 110 mm. It is not between two nodes (even outside the member) but inside the bounding box and meets

the part name or selection filtering criteria.

Nodal loads do not cause parts to bend.

Member load If a load does not meet the criteria for the nodal load, it is a member load. Member loads lie along the length of the member and cause member deformations.

Other loads Temperature loads are like line loads which affect an entire member. The left, right, top, and bottom surfaces of the member a temperature load affects define the direction of the load.

Load modeling codeUse the Options dialog box to determine the building code and safety factors Tekla Structures uses in load combination.

1. Click Tools > Options > Options... > Load modeling.2. Go to the Current code tab.3. Select the code in the Load modeling code list box.4. Change load combination factors on the appropriate tab if needed:

Tab Description More information

Current code The code to follow in analysis and load combination.

Additional information resourcesGetting Started with Analysis 30

5. Click OK.

Analysis methodYou can use either the linear (first order), or non-linear (second order, P-delta), analysis method in Tekla Structures. The non-linear method considers the non-linear nature of the geometry. This takes into account major deflections, but not the non-linear nature of materials. Tekla Structures treats materials as linear. See also Analysis method (65).

1.4 Additional information resourcesYou can find additional information related to Analysis & Design in the following locations:

Analysis & Design related webinars: http://www.tekla.com/international/solutions/building-construction/Pages/wednesdaywebinarcampaign.aspx

Eurocode The partial safety factors in limit states and reduction factors, for the Eurocode, based on load group types.

Load combination factors (69)

British The partial safety factors in limit states, for the British code, based on load group types.

AISC (US) The partial safety factors in limit states, for the US code, based on load group types.

UBC (US) Uniform building code, American code.

CM66 (F) The partial safety factors in limit states, for the French code for steel structures, based on load group types.

BAEL91 (F) The partial safety factors in limit states, for the French code for concrete structures, based on load group types.

IBC (US) International building code. American code.

ACI American Concrete Institute publication 318.

If you have to change the code during a project, you will also need to change the load group types and check load combinations.

Tab Description More information


Information on the analysis applications Tekla Structures links with: https://extranet.tekla.com/BC/tekla-structures-en/product/interfaces/Pages/Default.aspx

BasicsLoads 33

2 Loads

Introduction Once you have modeled physical structures by creating parts you can start adding loads. In Tekla Structures, you can create point loads, line loads, area loads with uniform or variable distribution. You can also model temperature, wind, and seismic loads. Either attach loads to specific parts or to locations.

In this chapter This chapter explains how to create and group loads. It also includes a general description of load groups, load types, and load properties. Load reference (47) contains step-by-step instructions for all load commands.

Assumedbackground

We assume that you have created a Tekla Structures model and have a basic understanding of modeling.

Contents This chapter is divided into the following sections:

Basics (33) Grouping loads (34) Load types and properties (37) Distributing loads (41) Working with loads (44) Load reference (47)

2.1 BasicsThis section presents some Tekla Structures vocabulary and concepts to help you start to model loads.

Load model A load model is the portion of the Tekla Structures model that includes all loads, together with the load group and building code information related to them. Each load in a load model has to belong to a load group. Each load can only belong to one load group. A load group can contain one or more loads.

Load group A load group is a set of loads that are treated alike during load combination. Load groups should contain loads caused by the same action and to which you want to refer collectively. Tekla Structures assumes that all loads in a group:

Have the same partial safety and other combination factors Have the same action direction Occur at the same time and all togetherSee Grouping loads (34) and Load combination (69).

Grouping loadsLoads 34

You need to create load groups because the same action can cause different types of loads, for example, point loads and area loads. See Load types (38). You can include as many loads as you like in a load group, of any load type.

Working withloads

In Tekla Structures, you can attach each load to a part for modeling purposes. You can also create floating loads that are bound to locations rather than parts. See Attaching loads to parts or locations (41).

Use the loads bounding box and part name filter or a selection filter to define which parts carry the load. See Applying loads to parts (42).

Topics Automatic loads and load groups (34)

Automatic loads and load groups

Self-weight Tekla Structures automatically calculates the self-weight of structural parts using the density of the material and the dimensions of the part.

To automatically include the self-weight of parts in load combinations, select the Include self-weight check box when you create load combinations. See Creating load combinations (72).

Wind loads Use the Wind load generator (28) tool to define the effects of wind on a structure. See Create Wind Load (55).

Seismic loads To automatically include seismic loads in the x and y directions in load combinations:

1. Define the code to follow in the seismic analysis.2. Define the load groups to include in the seismic analysis and their factors.

For more information, see Seismic analysis (66).

See also Load combination types (70)

Attaching loads to parts or locations (41)

2.2 Grouping loadsLoad groups should contain loads caused by the same action and to which you want to refer collectively. Tekla Structures assumes that all loads in a group:

Have the same partial safety and other combination factors Have the same action direction Occur at the same time and all together

Topics Load group properties (34)

Load group compatibility (35)

Working with load groups (36)

Load group propertiesTo define the properties of a load group, click the Load groups icon on the Loads and Analysis toolbar to open the Load Groups dialog box. The properties are:

Current When you apply loads in the model, Tekla Structures applies the Current load group. You can only define one load group as Current.


Name Each load group must have a unique name. Use load group names to define the visibility and selectability of loads. For example, you can select, modify, or hide loads based on their load group. See Filtering objects.

Type The type of a load group is the type of action that causes the loads.

Actions causing loads are building code specific. See Load modeling code (29). Most building codes use some or all of the following actions and load group types:

Permanent, dead, and/or prestressing loads Live, imposed, traffic, and/or crane loads Snow loads Wind loads Temperature loads Accidental and/or earthquake loads Imperfection loads

Direction The direction of a load group is the global direction of the action that causes the loads. Individual loads in a load group retain their own magnitudes in the global or local x, y, and z directions. See also Load magnitude (40).

Load group direction affects which loads Tekla Structures combines in load combination:

z direction groups are combined with both x and y direction groups. x or y direction groups are not combined with each other.

Color Use different colors for different load groups.

See also Load Groups... (47)



Load group compatibilityWhen Tekla Structures creates load combinations for structural analysis, it follows the building code you select in Tools > Options > Options... > Load modeling. See Load modeling code (29) and Load combination (69).

To accurately combine loads which have the same load group type, you need to identify which load groups:

Can occur at the same time (are compatible) Exclude each other (are incompatible)To define load group compatibility, click Load groups icon on the Loads and Analysis toolbar to open the Load Groups dialog box. Enter numbers to indicate compatibility.

Tekla Structures automatically determines and applies the self-weight of parts. See Automatic loads and load groups (34).


Compatibility Compatible load groups can act together or separately. They can actually be one single loading, for example, a live loading that needs to be split in parts acting on different spans of a continuous beam. Tekla Structures then includes none, one, several, or all of the compatible load groups in a load combination.

Incompatibility Incompatible load groups always exclude each other. They cannot occur at the same time. For example, a wind loading from the x direction is incompatible with a wind loading from the y direction. In load combination Tekla Structures only takes into account one load group in an incompatible grouping at a time.



Working with load groupsUse the Load groups dialog box to view, define, modify, and delete load groups. For example, this is where you set load group properties and indicate load group compatibility.

Click the Load groups icon on the Loads and Analysis toolbar to open the dialog box:

Checking loads and load groupsTo find out which load group a load belongs to, select the load in the model and click the Load groups by loads button. Tekla Structures highlights the load group in the dialog box.

Tekla Structures automatically applies basic compatibility facts, such as self-weight being compatible with all other loads, or live loads being compatible with wind load.

Tekla Structures does not combine loads in the x direction with those in the y direction.

Compatibility indicators are all 0 by default. It indicates that Tekla Structures combines the load groups as defined in the building code.

Load group types vary according to the code defined in Tools > Options > Options... > Load modeling. If you have to change the code during a project, you will also need to change the load group types and check load combinations.

Load types and propertiesLoads 37

To find out which loads belong to a load group, select the load group in the dialog box and click the Loads by load groups button. The associated loads are highlighted in the model.

If you have many loads in the model, you can show the group name and magnitude in the model view by right-clicking a load and selecting Inquire from the pop-up menu. Tekla Structures also highlights the parts that carry this load.

Changing the load groupTo move a load to a different load group, select the load in the model, then select a load group in the dialog box and click the Change load group button.

Importing and exporting load groupsTo use the same load groups in other models, you can import and export load groups.

Right-click on a load group in the Load Groups dialog box and select Export... from the pop-up menu to allow the load group to be used in other models.

Right-click on the load group list in the Load Groups dialog box and select Import... from the pop-up menu to use load groups from another model.


2.3 Load types and properties

Introduction Each load has a type and properties which define it (e.g. magnitude, direction, and distribution). This section describes the different load types and the properties of each load type.

Use the load properties dialog box to view or modify the properties of a load. Click Analysis > Properties > Loads and select a load type to open its properties dialog box.

Filtering byproperties

You can use load types and groups in filters. For example, you can select, modify, or hide loads based on their type and load group. See Filtering objects.

Topics Load types (38)


Load forms (39)

Load magnitude (40)

Temperature loads and strain (41)

See also Grouping loads (34)

Distributing loads (41)

Load typesTekla Structures includes the following load types:

Uniform load

Area load

Point load

Line loads

Load type Description

Point load A concentrated force or bending moment that can be attached to a part.


Load formsDistributed loads (line and area loads) can have different load forms.

Line load The load form of a line load defines how the load magnitude varies along the loaded length. The options are:

Line load A linearly-distributed force or torsion. By default it runs from a point to another point. You can also create a line load with offsets from the points. A line load can be attached to a part. Its magnitude can vary linearly across the loaded length.

Area load A linearly-distributed force bounded by a triangle or quadrangle. You do not have to bind the boundary of the area to parts. Area loads can have openings.

Uniform load A uniformly-distributed force bounded by a polygon. Uniform loads can have openings. You do not have to bind the polygon to parts.

Wind load An area load that can be defined for zones in the structure.

Temperature load A uniform change in temperature, that is applied to specified parts, and that causes axial elongation in parts.

A temperature difference between two surfaces of a part that causes the part to bend.

Strain An initial axial elongation or shrinkage of a part.

To ensure that load analysis is correct, use area and uniform loads for loads on floors. For example, when the layout of beams changes, Tekla Structures recalculates the loads to the beams. It will not do this if you use point or line loads on individual beams.

Load type Description

Option Description

The load magnitude is uniform across the loaded length.

The load has different magnitudes at the ends of the loaded length. The magnitude changes linearly between the ends.


Area load The load form of an area load defines the shape of the loaded area. It can be:

For information on how to define the length or area a load affects, see Loaded length or area (43).

See also Load magnitude (40)

Load magnitudeLoad magnitude can occur in x, y, and z directions. The coordinate system is the same as the current work plane, so positive coordinates indicate a positive load direction. See Work plane.

For example, when you create loads perpendicular to sloped parts, shifting the work plane helps you to place loads accurately. See Defining the work area.

Some types of loads can have several magnitude values. For example, the magnitude of line loads may vary along the loaded length. See Load forms (39).

In the load properties dialog boxes, the following letters denote magnitudes of different types:

P is for a force acting on a position, along a line, or across an area. M is for bending moments acting on a position or along a line. T is for torsional moments acting along a line.

The load magnitude changes linearly, from zero at the ends of the loaded length, to a fixed value in the middle of the loaded length.

The load magnitude changes linearly, from zero at one end of the loaded length, through two (different) values, back to zero at the other end.

Option Description

Option Description

Quadrangular

Triangular

Distributing loadsLoads 41

Temperature loads and strainTemperature loads can be caused by:

An increase or decrease in temperature A difference in temperature between the top and bottom surfaces of a part A difference in temperature between the sides of a partTemperature changes cause axial elongation or uniform volume expansion in parts.

Different surface temperatures cause parts to bend.

Strain Strain is an initial axial elongation (+) or shrinkage (-) of a part.

To define the temperature loads and strain that affect parts, click Analysis > Properties > Loads > Temperature Load... and use the Magnitude tab.

See also Create Temperature Load (54)

2.4 Distributing loadsThis section explains how to attach loads and how to define which parts, or lengths and areas of parts, carry loads.

Topics Attaching loads to parts or locations (41)

Applying loads to parts (42)

Loaded length or area (43)

Attaching loads to parts or locationsYou can attach loads to parts or locations for modeling purposes.

Attaching a load to a part binds the load and the part together in the model. If the part is moved, copied, deleted, etc., it affects the load. For example, a prestressing load moves with the part to which it is attached, and disappears if the part is deleted.

If you do not attach a load to a part, Tekla Structures fixes the load to the position(s) you pick when you create the load.

To attach a load to parts or locations, open the load properties dialog box. On the Distribution tab, select an option in the Load attachment list box:

Option Description

Attach to member Attaches the load to a specific part. If the part is moved, copied, deleted, etc., it affects the load.

Dont attach The load is not attached but it is considered a floating load. This load is bound to the position you pick when you create the load, not to parts.


To define which parts carry a load, see Applying loads to parts (42).

Applying loads to partsIn order to apply loads in the structural analysis model, Tekla Structures searches for parts in the areas that you specify. For each load, you can define the load-bearing parts by name or selection filter, and the search area. To do this, open the loads properties dialog box and click the Distribution tab.

Load-bearingparts

To define the load-bearing parts by name:

1. In the Load-bearing parts list box: Select Include parts by name to define the parts that carry the load. Select Exclude parts by name to define the parts that do not carry the load.

2. Enter the part names.

To define the load-bearing parts by selection filter:

1. In the Load-bearing parts list box: Select Include parts by filter to define the parts that carry the load. Select Exclude parts by filter to define the parts that do not carry the load.

If you select the Attach to member option, you must select the part before picking the position for the load.

You can use wildcards when listing the part names. See Wildcards.


2. Select the selection filter in the second list box.

For more information on selection filters and filtering, see Filtering objects.

Bounding box Use the loads bounding box to define the area to search for the parts that carry the load. The bounding box is the volume around the load that Tekla Structures searches for load-bearing parts.

Each load has its own bounding box. You can define the dimensions of a bounding box in the x, y, and z directions of the current work plane. The dimensions are measured from the reference point, line, or area of the load. See also Handles (45).

Offset distances from the reference line or area do not affect the size of the bounding box. See Loaded length or area (43).

See also Each loads load panel properties also affect which parts receive the load. See Modifying load distribution (43).

Loaded length or areaIf a line, area, or uniform load affects a length or area which is difficult to select in the model, select one close to it. Then use the values in the Distances fields in the load properties dialog boxes to pinpoint the length or area. You can shorten or divide the loaded length, and enlarge or reduce the loaded area.

Line load To shorten or divide the length of a line load, enter positive values for a and b.

Area load To enlarge the area an area load affects, enter a positive value for a. To reduce the area, enter a negative value.

Modifying load distributionBy default, Tekla Structures distributes loads using the panel method. To modify the way loads are distributed, modify the properties on the Load panel tab in the load properties dialog box. The properties are:


Spanning Single: in the direction of the primary axis only

Double: along the primary and secondary axes

Primary axis direction

If Spanning is set to Single, you can define the primary axis direction by selecting a part in the model and setting this option to Parallel to part or Perpendicular to part.

To manually define the primary axis weight when Spanning is set to Double, you must also define the primary axis direction.

Working with loadsLoads 44

Example When using double spanning, automatic primary axis weight and the weight value affect the proportions of the load which is applied to the primary axis and to the perpendicular axis.

If Automatic primary axis weight is Yes, the proportions will be in proportion to the third power of the span lengths in these two directions, i.e. the shorter the span, the bigger the proportion of the load. The Weight value does not matter.

If Automatic primary axis weight is No, the given Weight value (0.50 in this example) is used to divide the load.

2.5 Working with loadsTo modify the properties of a load, double-click it in the model to open the relevant load properties dialog box.

Automatic primary axis weight

Yes: Tekla Structures automatically calculates the load portions for primary and secondary directions.

No: Enter the weight for the primary direction in the Weight field. Tekla Structures calculates the weight for the secondary direction by subtracting this value from 1.

Load dispersion angle

The angle by which the load is projected onto the surrounding elements.

Use continuous structure load distribution

Yes: for uniform loads on continuous slabs. For the first and last spans, the distribution of support reactions is 3/8 and 5/8, instead of 1/2 and 1/2.

No



When you have finished, click Modify to update the properties of the load in the model.

Topics Changing loaded length or area (45)

Scaling loads in model views (45)

Defining varying wind loads (46)

Changing loaded length or areaAs well as changing load properties, you can modify loads by:

Moving line load ends Moving uniform load corners Changing the shape of openings in loads Adding corners to uniform loads

Handles Tekla Structures indicates the ends and corners of line, area, and uniform loads using handles. When you select a load, the handles are magenta.

You can use these handles to move load ends and corners:

1. Select the load to display its handles.2. Click the handle you want to move. Tekla Structures highlights the handle.3. Move the handle(s) like any other object. See Moving an object. If you have Drag and drop on,

just drag the handle to a new position. See Moving an object using drag-and-drop.

To add corners to uniform loads, use the Modify Polygon Shape command. See Modifying the shape of a polygon.

Scaling loads in model viewsYou can have Tekla Structures scale loads when you are modeling. This ensures that loads are not too small to see, or so large that they hide the structure.

To scale loads in model views, click Tools > Options > Options... > Load modeling and go to the Arrow length tab:


Example You define that point loads with magnitude of 1 kN or less are 250 mm high in the model, and point loads with magnitude of 10 kN or more are 2500 mm high. Tekla Structures linearly scales all point loads that have a magnitudes between 1 kN and 10 kN between 250 mm and 2500 mm.

Defining varying wind loadsThe Create Wind Load (55) command allows you to define which zones have concentrated wind load. Each zone is the height of the wall. Define the width of the zone using either dimensions or proportions. You can define up to five zones for each wall.

In the example below, the loads in the global x direction are multiplied by 3 at both corners of wall 1.

Load referenceLoads 47

The Wind load generator (28) dialog box contains one tab for each wind direction.

2.6 Load referenceThis section consists of the reference pages for the load commands.

To create loads, use the icons on the Loads and Analysis toolbar or select a command from the Analysis > Loads menu. The following table lists the commands for creating loads and gives a short description of each one.

Load Groups...

Synopsis This command displays the Load Groups dialog box that you can use to manage load groups.

Command Icon Description

Load Groups... (47) Displays the Load Groups dialog box.

Create Point Load (49) Creates a point load at a picked position.

Create Line Load (50) Creates a line load between two picked points.

Create Area Load (51) Creates an area load using three picked points.

Create Uniform Load (53)

Creates a uniformly-distributed polygonal area load using at least three picked points.

Create Wind Load (55) Creates wind loads on a structure.

Create Temperature Load (54)

Defines a temperature change in a part, or a temperature difference between two part surfaces.


Description Tekla Structures lists all the existing load groups in the Load Groups dialog box. Use the dialog box to view, define, modify, and delete load groups.

Usage Click Analysis > Loads > Load Groups....

To define a new load group:

1. Click Add.2. Select the default load group from the list.3. Click the load group name to modify it.4. Click the load group type and select a type from the list box.5. Click the load group direction to modify it.6. To indicate compatibility with existing load groups:

In the Compatible column, enter the number you have used for the load groups that are compatible with this load group.

In the Incompatible column, enter the number you have used for the load groups that are incompatible with this load group.

7. Click OK to close the dialog box.

To modify an existing load group:

1. Select the load group from the list.2. Change the name, direction, group type, or compatibility indicators.3. Click OK to close the dialog box.

To delete a load group:

1. Select the load group from the list.

Column Description More information

Current The @ symbol identifies the current load group. To change the current load group, select a load group and click the Set current button.

Load group properties (34)

Name Unique name of the load group.

Type Load group type, based on the action that causes the loads in the group.

Direction Direction of the action that causes the loads in the load group.

Compatible A number that identifies all the load groups that are compatible with each other.


Incompatible A number that identifies all the load groups that are incompatible with each other.

Color The color that Tekla Structures uses to show the loads in the group.

Load group properties (34)


2. Click Delete.3. Click OK in the warning dialog box. This also deletes the loads in the load group.

To find out which loads belong to a load group:

1. Open the Load Groups dialog box.2. Select a load group in the dialog box.3. Click the Loads by load groups button. Tekla Structures highlights the loads in the model.

To find out which load group a load belongs to:

1. Open the Load Groups dialog box.2. Select a load in the model.3. Click the Load groups by loads button. Tekla Structures highlights the load group in the dialog

box.

To move a load to a different load group:

1. Select the load in the model.2. Select a load group in the Load Groups dialog box.3. Click the Change load group button.

To export load groups:

1. Select the load groups to export in the Load Groups dialog box.2. Right-click and select Export... from the pop-up menu.3. In the Export Load Groups dialog box, browse for a folder and enter a name for the load group

file.4. Click OK.

To import load groups:

1. In the Load Groups dialog box, right-click on the load group list and select Import... from the pop-up menu.

2. In the Import Load Groups dialog box, browse for the load group files (.lgr) to import.3. Click OK.

See also Working with load groups (36)

Grouping loads (34)

Create Point Load

Synopsis This command creates a point load at a position you pick.

When you delete a load group, Tekla Structures also deletes all the loads in the load group.

If you try to delete the only load group, Tekla Structures will warn you. At least one load group must exist.

You can include several load groups in one load group file.


Preconditions Shift the work plane to create loads perpendicular to sloped parts.

Description Tekla Structures creates the point load using the properties in the Point Load Properties dialog box. The filename extension of a point load properties file is lm1.

Usage 1. Double-click the Create point load icon.2. Enter or modify the load properties.3. Click Apply or OK to save the properties.4. If you have selected the Attach to member option, select the part to attach the load to.5. Pick the position of the load.

See also Points

Creating a point

Using commands

Create Line Load

Synopsis This command creates a line load between two picked points.

Preconditions Shift the work plane to create loads perpendicular to sloped parts.

Description Tekla Structures creates the line load using the properties in the Line Load Properties dialog box. The filename extension of a line load properties file is lm2.

Field Description More information

Load grou

Documents

Analysis Guide 180 Enu