LSPP Geometry

Introduction to LS-PrePost Geometry Quanqing Yan, Philip Ho, LSTC March, 2013

Geometry Terms

LS-PrePost 3.x/4.x uses a new geometry engine

• Open CASCADE Technology (http://www.opencascade.org)

Terminology

• Vertex: a point in 3D space

• Edge: a curve bounded by two vertices

• Closed Edge: an edge with only one vertex

• Wire: a curve constructed from multiple edges

• Face: a surface bounded by one or more wires

• Infinite face: a face with no bounding wires

• Shell: one or more faces with shared edges

• Solid: one or more shells with no open faces

• Compound Solid: one or more combined solids

LS-PrePost Geom | March 2013 2 ©2013 Livermore Software Technology Corporation

Geometry General Selection

LS-PrePost Geom | March 2013 3

Pick Select a single entity

Area Select using a rectangular window

ID Manually key-in entity IDs

In Select entities inside Area/Poly

Out Select entities outside Area/Poly

Add Add entities to a selection set

Rm Remove entities to a selection set

Clear Clear selection

Save Save selection to buffer

Load Load selection from buffer

Deselect Undo last selection

Whole Select all entities in model

Visible Select all visible entities

Reverse Reverse selection

Filters are provided because geometry objects often overlap (ex:

Edges and Wires). Data types can be turned on/off using the

filters so that the desired selection can be made

©2013 Livermore Software Technology Corporation

Clear all filters, Select all filters

Reference Axis, Vertex

Reference plane, Edge

Reference point, Wire

Reference coord, face

Fem node, Shell/Solid

Reference Geometry Toolbar Reference geometry is used to define

the form and/or shape of other geometry entities, it consists of

Reference points

Reference axes

Reference planes

Reference coordinate systems

GemEdit is an interface use to edit the reference geometry entities


Ref. Geometry → Axis Purpose: create a reference axis using one of the

following methods... Parameters – create axis with a point and a direction

Line – create axis with a line or an edge

Planes Intersect – create axis from the intersection of two planes

Axis of Revol – create axis from the axis of a cylinder, cone, or revolute object

Tangent Cur – create axis that is tangent to a curve at a point on a curve

Point to Plane – create axis that passes through a point and is normal to a plane

Nor to Surf – create axis that passes through a point on a surface and is normal to the surface


Ref. Geometry → Plane Purpose: create a reference plane using one of the

following methods... Parameters – create plane with a point and a normal

Through Line/Point – create plane through a point and normal to the selected line

Parallel with Point/Plane – create plane through a point parallel to a plane or face

Rotate plane – Create a plane by rotating a selected plane with a selected axis

Offset Plane – create plane by offsetting another plane

Normal to Curve – create plane through a point and perpendicular to an edge or a curve

Tangent with Surface – create plane that is tangent to a non-planar surface

3 Points – create plane containing 3 points

2 Points – create a plane normal to the direction by 2 points


Ref. Geometry → Coordinate System Purpose: create a reference coordinate system using

one of the following methods... Parameters – create coordinate system by defining a origin point,

a Z direction, and an X direction

Origin/Direction – create coordinate System by picking an origin point, an axis as Z-direction, and an axis as X-direction

In Cur/Surf - Create a coordinate system by select an point on the selected curve or the selected surface

3 Points – create a coordinate system by 3 points, can choose type as XOY, YOZ, or ZOX

Sample Cur – Create a series of coordinate systems on the selected surface

Principal Axes – create a principal axes coordinate system by the selected entities


Ref. Geometry → Point Purpose: create a reference point using one of the

following methods... Parameters – Create a point by coordinates

Cir/Sph/Con – Create point using center of circle, ellipse, parabola, hyperbola, sphere, torus, or apex. of cone.

Barycenter – create a reference point at the gravity center or parameter center of the selected shape

Cur/Cur Inter – create reference points at the intersection of the two selected curves or ref-axes. You can select edge or reference axis

Cur/Surf Inter – create reference points at the intersection of the two selected curve and surface. You can select edge, reference axis, face and reference plane

To Cur/Surf – create reference points by picking position on edge or face

3 Points Arc – create reference point which locates at the center of the arc


Ref. Geometry → Point Purpose: create a reference point using one of the

following methods Sample Cur – Sample points from curves

Sample Surf – Sample point from surface, sampling methods:

• Uniform method

• Curvature method

• Control points method

Point Avg – create point at the geometry center of the selected points

Middle Point – create a ref. point between two selected points


Geometry → Curve Toolbar Curve Toolbar consists of interfaces to create

and manipulate point and curves entities

Point – a vertex

Line, Circle, Circular Arc, Ellipse, Elliptical Arc, Bspline Curves, Helis/Spiral, Wire (composite curve) – Many different methods are available to create these entities

Middle Curve, Fillet Curve, Parabola, Hyperbola, Function, Polygon, Sketch – are different ways to create curves

Break, Merge, Bridge, Smooth, Convert – are different ways to manipulate curves


Curve → Point Purpose: create a point using one of the following

methods... Parameters – create point by entering X, Y, Z coordinates (or

click a position on a plane when “Sketch on Plane” is checked)

Project to Curve – create point by projecting a point onto a curve

Project to Surface – create point by projecting a point onto a surface

Edit Curve End – Edit curve's end by selecting vertex and freely dragging. The curve must be from independent edge or edge from independent wire

Edit Ctrl-Pnt – Edit b-spline curve or b-spline surface by modify their control points. You can modify the curve or surface by dragging, adding or removing control points.

Batch Input – Input a series of x,y,z coordinates into the text widget


Curve → Line Purpose: create a line using one of the following

methods... Parameters – create line by entering X, Y, Z coordinates of 2

end points

Point/Point – create line segments by picking points. If more than 2 points are selected and “Closed” is active, a closed loop will be created.

Point/Axis – create line by picking a point and defining a “Length” along an axis. A negative length will reverse the direction.

Point/Circle – Create two lines which pass the point and tangent with the circle. The selected point must locate at the plane of the circle.

Circle/Circle – Create lines which tangent with two circles. If two circles intersect with each other, it will also create the intersecting line. The selected two circles must locate at the same plane.


Curve → Line Purpose: create a line using one of the following

methods... Middle Line – Create lines which pass through the intersection

of two selected lines and have the same angle with two selected lines.


Curve → Circle Purpose: create a circle using one of the following

methods... Parameters – create circle by entering a center point, a normal

direction, and a radius

Point/Axis – create circle by selecting a center point and a normal axis

Coordinate – create circle by selecting a coordinate system

3 points – create circle by selecting 3 points

Tan Line/Circle – create circles tangent with the selected line and circle, it also need to define radius.


Curve → Circular Arc Purpose: create a circular arc using one of the following

methods... Parameters – create circular arc by entering a center point, a

normal direction, a start direction, a radius, and start and end angles

Point/Axis – create circular arc by selecting a center point and a normal axis

Coordinate – create circular arc by selecting a coordinate system

3 point – create circular arc by selecting 3 points


Curve → Ellipse Purpose: create an ellipse using one of the following

methods... Parameters – create ellipse by entering a center point, a

normal direction, a start direction, and major and minor radii

Point/Axis – create ellipse by selection a center point and a normal axis

Coordinate – create ellipse by selecting a coordinate system


Curve → Elliptical Arc Purpose: create an elliptical arc using one of the

following methods... Parameters – create elliptical arc by entering a center point, a

normal direction, a start direction, major and minor radii, and start and end angles

Point/Axis – create elliptical arc by selecting a center point and a normal axis

Coordinate – create elliptical arc by selecting a coordinate system


Curve → BSpline Purpose: create a b-spline using one of the following

methods... Interpolation Points – create b-spline by interpolating selected

points. If more than 2 points are selected and “Closed” is active, a closed loop will be created.

Curve on Surface – create b-spline by interpolating selected points on a surface

Sketch on Mesh – create b-spline by interpolating selected nodes

Curve from Mesh – create b-spline by selecting nodes

Shell Intersection – create b-spline at the intersection of 2 FE shell parts

Snap Edge End – snap the end points of unconnected b-splines together


Curve → Helix Purpose: create a helix using one of the following

methods... Distance and Loop – create helix by entering distance between

loops and number of loops. A circle or arc must also be selected.

Height and Loop – create helix by entering total height and number of loops

Height and Distance – create helix by entering total height and distance between loops


Curve → Wire (Composite Curve) Purpose: create a wire using one of the following

methods... Edge list – create wire by connecting edges together

Bounds of shell – create wire by using the boundary of a shell


Curve → Break Purpose: break a curve into multiple sub curves using

one of the following methods... Auto Break – split curve automatically by defining a feature

angle

Manual Break – split curve by picking positions on the curve

Batch Break – split multiple curves on faces by defining a feature angle

Parameter -


Curve → Merge Single - To merger several neighbor curves into a

single curve, select the curves. In fact, it's not necessary to select curves in order

Multiple - Merge curves into several bspline curves according to gap tolerance. If the merged curves are not smooth, check "Refitting" to refit the merged curves.


Curve → Bridge Purpose: bridge curves together according to the

module length of the tangent directions


Curve → Smooth Purpose: smooth a noisy curve by entering an

appropriate tolerance. A new curve can be created if “Copy” is active.

If selected multi-curves can be merged into one edge, you can check "Group Smooth" to smooth the merged curve. To smooth curve to piecewise b-spline curve, check "Polygon Smooth".


Curve → MidCurve Purpose: create a new curve between 2 existing curves.

The location of the new curves can be defined as a percentage from the first curve. A mid point can also be created using this interface.


Curve → Morphing Purpose: to morph a curve to new position, 4 methods

are provided:

Segment - Define a segment by selecting two points on the curve and morph this segment by picking one point.

Control point - Select a curve , the control point of this curve will show, pick the control point to morph the curve.

Curve point - Select a curve, the curve points will show, pick the curve point to morph the curve

Global - Select a curve and smooth it by adjusting smoothness factor


Curve → Fillet Purpose: to create fillet curves among several curves

using Fillet Curve


Curve → Parabola Purpose: to create parabola by several construction

types

Parameters - Create parabola by center, normal, start direction, focal, start and end parameters

Point/Axis - Create parabola by selecting a point, an axis and define the start and end parameters

Coordinate System - Create parabola by selecting a point, an axis and define the start and end parameters


Curve → Hyperbola Purpose: to create hyperbola by several construction

types

Parameters - Create hyperbola by center, normal, start direction, major and minor radius, start and end parameters

Coordinate System - Create hyperbola by selecting a coordinate system, and define the major and minor radius, start and end parameters


Geometry – Surface Toolbar Surface toolbar consists of interfaces to create

and manipulate surface entities Plane, Cylinder, Cone, Sphere, Torus, Ellipsoid – many different

methods are available in each of the interface to create these basic surface entities

Fill Plane, Extrude, Revolve, Sweep, Loft, N-side Surface, Patch Surface, Bridge, Combine, Morph Surface, – are different way to create surfaces

Fit Surface – to fit (approximately) a surface over a set of nodes, or mesh (elements), or curves

Mid-Surface – to create the mid surface from a Solid object

Morph surface – to morph an existing surface into a new surface by moving surface points, or control points, or profile curves


Surface → Plane Purpose: create a planar surface using one of the

following methods... Parameter – Create a plane by parameters. The parameters

contain a local coordinate system, start and end X, Y coordinates on the local coordinate system. Default, the coordinate system is set as the standard global coordinate system. You can also sketch a rectangle plane onto any plane when "Sketch on Plane" is checked

3 points – 3 points to define a plane

Fit Plane – create plane by fitting through selected points


Surface → Plane Purpose: create a planar surface using one of the

following methods... Point/Normal – Create a plane by a point and a normal

Parrallelogram - Create a parallelogram plane by two connected curves.

IsoTrapezoid - Create a isotrapezoid plane by two connnect curves

RegPolygon - Create a regular polygon's plane by side number and side length.


Surface → Cylinder Purpose: create a cylindrical surface using one of the

following methods... Parameter – create cylinder by selecting a coordinate system,

entering a radius, and entering start and end angles

Bottom/Top Center – create cylinder by selecting points at the bottom center and top center


Surface → Cone Purpose: create a conical surface using one of the

following methods... Parameter – create cone by selecting a coordinate system,

entering a semi angle of apex, entering a bottom radius, entering start and end angles, and entering the bottom and top height (from the origin of the coordinate system)

Bottom/Top Center – create cone by selecting points at the bottom center and top center


Surface → Sphere Purpose: create a spherical surface using one of the

following methods... Parameter – create sphere by selecting a coordinate system

and entering the radius, the start and end U angles, and the start and end V angles

Center Point – create sphere by selecting a center point and a point on the sphere (or by entering a radius)

Tetrahedron - Select four points to create circumscribed or inscribed sphere


Surface → Torus Purpose: create a toroidal surface by selecting a local

coordinate system (default is global) and entering the following parameters...

Path radius

Profile radius

U start and end angles

V start and end angles


Surface → Fill Plane Purpose: create a surface by connecting edges or points

to fill a plane... By Edges – edges will be used for the boundary of the surface

By Points – straight lines will be created between points


Surface → Extrude Purpose: create a surface by extruding an edge or a

wire using the following steps... Pick edge/wire as the profile

Pick another edge or axis as the direction

Enter start and end distances


Surface → Revolve Purpose: create a surface by revolving an edge or a wire

using the following steps... Pick edge/wire as the profile

Pick an axis of revolution

Enter start and end angles


Surface → Sweep Purpose: create a surface by sweeping an edge or a

wire using the following steps... Pick edge/wire as the profile

Pick a curve that defines the sweep path

To create a sweep surface, select a edge or wire as path curve. You can check "End Constraint" to make profile curve connected with path curve on one end. If the path curve is noisy, you can also check "Smooth Path" to make the path smooth. To set surface continuity, check "Set Continuity


Surface → Loft Purpose: create a lofted surface. A loft is a face or

shell passing through a set of sections in a given sequence. Usually, sections are edges or wires, but the first and the last sections may be vertices (punctual sections).


Surface → N-Side Purpose: create a surface from a set of (N) bounding

edges. Constraints can be applied as follows... Continuity 0 – the surface must pass by 3D representation of

the edge

Continuity 1 – the surface must pass by 3D representation of the edge, and it must respect tangency with the first face of the edge

Uniform Fit – the surface has to pass by 3D representation of

the edge. It's created by fitting a uniform base-surface, and

use raw edges to trim base-surface

Auto Close – automatically connect each neighboring edge

Smooth Curve – smooth boundary curves


Surface → Patch Surface Purpose: create a surface from a region bounded by

contiguous b-spline curves. The algorithm accepts 2, 3, or 4 bounding curves. A range of filling styles (flat, middle, round, constrained) are available.

Constrained will use fit method to get a proper surface


Surface → Bridge Purpose: create a surface by bridging faces using the

following steps... Select an edge from one face

Select an edge from another face


Surface → Combine Purpose: create a surface by combining neighboring

faces or shells using the following steps... Select faces or shells

Define number of U, V control points

Define degrees, max tolerance, and smoothness

Select final surface type (Natural or Trimmed)

Activate "Replace Raw Faces" to remove original faces

Activate "Preview" to preview result


Surface → Fit Surface Purpose: create a fitted surface based on an FE mesh,

nodes, or curves


Surface → Mid Surface Purpose: create a mid surface from a solid or from top

and bottom surfaces By Surfaces – manually create a mid surface from two surfaces

By Solid – automatically create all mid surfaces from a solid object (with limitations)


Geometry – Solid Toolbar Solid toolbar consists of interfaces to create

and manipulate solid entities

Box, Cylinder, Cone, Sphere, Torus - many different methods are available in each of the interface to create these basic solid entities

Extrude, Revolve, Sweep, Loft, Fillet, Chamfer, Draft, Thicken, Wedge, Boolean, Prism – are different way to create solid objects with tools


Solid → Box Purpose: create a solid box using one of the following

methods... Parameters – create box by selecting a coordinate system

(default is global) and entering min and max X, Y, Z coordinates

2 Points – create box by selecting 2 points located at opposing corners

Boundbox – create a box originally from a bounding box of selected items. Four options are "By Shapes", "By FEM", "By Assembly", "Whole Model".


Solid → Cylinder Purpose: create a solid cylinder using one of the

following methods... Parameters – create cylinder by selecting a coordinate system

(default is global) and entering a radius, height, and angle

Bottom/Top Center – create cylinder by selecting points at the bottom center and top center


Solid → Cone Purpose: create a solid cone using one of the following

methods... Parameters – create cone by selecting a coordinate system

(default is global) and entering bottom and top radii, height, and angle

Bottom/Top center – create cone by selecting points at the bottom center and top center


Solid → Sphere Purpose: create a solid sphere using one of the

following methods... Parameters – create sphere by selecting a coordinate system

(default is global) and entering a radius, U start and end angles, and V start and end angles

Center Point – create sphere by selecting a center point and a point on the sphere (or by entering a radius)


Solid → Torus Purpose: create a solid torus by selecting a local


Path radius

Profile radius

U start and end angles

V start and end angles


Solid → Extrude Purpose: create a solid object by extruding surfaces in a

specified direction. The direction can be a reference axis, a line, or an edge.


Solid → Revolve Purpose: create a solid object by revolving a group of

faces about an axis


Solid → Sweep Purpose: create a solid object by sweeping a surface

along a curve User can check "End Constraint" to make profile connected with

path curve on one vertex. If the path curve is noisy, one can also check "Smooth Path" to make the path smooth.


Solid → Loft Purpose: create a solid object by lofting through a set

of closed sections in a given sequence. Usually, sections are edges, wires, or faces, but the first and the last sections may be vertices (punctual sections).


Solid → Fillet Purpose: creates rounded internal or external faces on

shell or solid shapes. Fillets can be applied to all edges of a face, selected sets of faces, selected edges, or edge loops. “Equal Radius” or “Various Radius” can be used. If “Whole Shape” is active, the entire solid will be filleted.


Solid → Chamfer Purpose: create beveled edges using one of the

following methods... Angle-Distance – create chamfer by defining distance and an

angle

Distance-Distance – create chamfer by defining a pair of distances


Solid → Draft Purpose: create tapered faces using a specified angle.

One application is to make a molded part easier to remove from a mold. A draft can be inserted in an existing part, or a draft can be applied while extruding a feature. Drafts can be applied to solid or surface objects.


Solid → Thicken Purpose: create a solid object by thickening one or

more adjacent shell or solid surfaces using the following steps...

Select a solid object

Select faces that will be removed for thickening


Solid → Wedge Purpose: create a solid wedge by selecting a local


Length

Width

Height

Min and Max coordinates


Solid → Prism Purpose: create a solid prism or pyramid by defining no.

of sides, side length, and the height Prism – same section on both ends

Pyramid – one end is a single point

Draft – one end is bigger or smaller


Solid → Boolean Purpose: combine, subtract, or find the common space

occupied by two solid objects


Geometry – GeoTool Toolbar GeoTool toolbar consists of interfaces of

necessary tools that repair, manipulate, and manage the geometry entities


GeoTool → Delete Entities Purpose: to delete geometry entities including

reference geometry Any mode – delete any geometry object

Face mode - can perform delete and repair or delete and fill

To clear specified types of entities, check specified filters and

click "Clear".

Remove Blank - To delete all blank shapes

Repair Mode – to replace a complex edge from face with a simple edge


GeoTool → Blank Entity Purpose: to blank any geometry entity Checking the filters, a specific type of geometry entity can be

blanked or unblanked

Blank Independent – when this option is checked, the independent shape will be blanked, such as selecting a face from a solid, the solid will be blanked


GeoTool → Extend Curve Purpose: to extend a curve by selecting Distance – extend curve by a distance

Up to face – extend curve to a face

Up to edge – extend curve to an edge

Up to Vertex – extend curve to a vertex

Extension Type:

Linear – extend curve tangent to the original curve

Same Curve – extend curve using existing curvature

Extend on surface – extend curve on the face (if the curve is located on a face)


GeoTool → Extend Surface Purpose: to extend a surface by selecting en edge on a

face or a face Stop Condition:

Distance – extend surface by a distance

Up to Face – extend surface to a face

Up to Vertex – extend surface to a vertex

Extension Type:

Linear – extend surface tangent to the original face

Same Surface – extend surface using existing curvature


GeoTool → Intersection Purpose: to create entities at the intersection of two

geometry data sets using one of the following methods...

Standard – create intersections of data in set 1 with set 2

Mutual – create intersections within a single set of data

Note: a vertex will be created when a curve intersects another curve or a surface. A curve will be created when a surface intersect another surface.


GeoTool → Offset Purpose: to create geometry offsets using one of the

following methods... Face/Shell – select a face or shell, enter an offset distance, and

activate the “Round Corner” option

Plane Edge/Wire – select planar edge/wire and enter an offset distance. The resulting edge/wire will be in the same plane.

Edge on Face – select edges from a face and enter an offset distance. The resulting edge will locate on the same surface.


GeoTool → Project Purpose: to project vertices, edges, and wires onto a

face or shell Normal Projection – first select a destination face/shell. Then

select a vertex/edge/wire. Finally, select a line or an axis as the projection direction. If a direction is omitted, LS-PrePost will test to see if the destination object is planar. If yes, the normal of the destination object will be used. If no, LS-PrePost will test to see if the source object is planar.

Conical Projection – Select the conical vertex as the view point

Closest Projection – project with minimum distance


GeoTool → Replace Face Purpose: to replace a face using the following steps... Create a new surface using N-Side surface

Select surfaces to be replaced with the new surface


GeoTool → Stitch Purpose: to stitch independent faces into a shell Try to Make Solid – convert the shell to a solid if it forms an

enclosed volume

All Faces – select all faces from the current model

Dis Tol – set distance tolerance to control the stitching

Non-manifold Mode – stitch faces that come together in a T-configuration

Group by Part – stitch faces that belong to the same part

Decompose – will unstitch the object into independent faces


GeoTool → Trim Purpose: to use edges or faces to trim other edges or

faces, or solid Standard – define a trim tool and select entities to be trimmed.

Activate “Raw Trim Tool” to extend the tool if it does not reach the entities to be trimmed

Mutual – Trims faces or edges with each other in the listbox

Split face – split a face by picking 2 face edge points



faces, or solid

Cut solid – Cut a solid shape by a ref-plane or any face. If the

selected face is not totally cross the solid, you can check "Raw

Trim Tool" to extend the trim tool face



faces, or solid Cut Model – select a cutting plane to cut whole model

Multi Trim – select multiple trim tools to trim an edge, a wire or a face


GeoTool → Transform Purpose: to perform standard 3D transformations Translate – translate geometry objects in a specified direction

Rotate – rotate geometry objects about an axis

Scale – scale geometry objects about a reference point

Mirror – reflect geometry objects about a reference point/axis/plane

Transform – transform geometry objects from one coordinate system to another

Copy – create new geometry entities while performing transformations


GeoTool → Reverse Purpose: to reverse the direction of the entity For edge/wire – it is the direction of the curve

For face – it is the direction of the normal

Reverse Arrow Color – will toggle the color of the arrow in Green and Cyan


GeoTool → Copy Purpose: to move or copy geometry entities from one

assembly to another assembly To Current Assembly – new geometry entities will be created in

the current assembly

To New Assembly – new geometry entities will be created in a new assembly

To Specify Assembly – new geometry entities will be create in a specified assembly

Move to Specify Assembly – geometry entities will be moved from one assembly to another


GeoTool → Manage Purpose: to manage geometric entities (un)Blank – blank or unblank independent entities

Delete – delete independent entities (you can't delete a face from a shell or an edge from an face)

(un)BlkAll – blank or unblank the whole model

Export – export entities in IGES or STEP format

SplitShell – split all shells and solids into independent faces

Glo/Loc – Glo lists only independent objects, Loc lists all

To 2.x – convert points/curves/surfaces to version 2.4 data structure

Undo – undo last (un)Blank or Delete operation

ClearModel – remove all geometry objects and reference geometry from current model


GeoTool → Heal → Face Purpose: to fix problems related to faces Duplicate – find duplicate or overlap faces and remove them

when Apply is clicked

Small face – find faces that their size is smaller than the specified threshold

Narrow face – find long and narrow faces according to the specified aspect ratio and size

Analysis – click this button the perform checking

Apply will removed the found faces


GeoTool → Heal → Edge Purpose: to fix problems related to edges Toggle – stitch neighboring faces by selecting a seed edge

Untoggle – unstitch neighboring faces

Replace – replace a raw edge with another edge

Small Edges – find small edges

Break – break an edge into several edges according to the angle threshold

Duplicate – find and remove duplicate or overlay edges

Suppress – tag an edge to suppress it from the topology such that in the Auto Meshing, the tagged edge will not be a boundary


GeoTool → Heal → Vertex Purpose: to fix problems related to vertices Add – insert a vertex into an edge (break the edge into two sub

edges at the new vertex)

Move – move a vertex on an edge to a specified position (the new position should not be far away)

Remove – search and remove redundant vertices according to a specified break angle

Duplicate – search duplicate vertices and remove them

(Un)Suppress – suppress and un-suppress vertices such that they will not or will be considered in the Auto Meshing


GeoTool → Heal → Hole Purpose: to find and remove holes Inner hole – find and remove holes that are entirely within a

single surface

Outer hole – find and remove holes that are located on multiple surfaces or on the outer boundary of a surface

Hallow hole – find hollow region shell or solid


Outer hole

Inner Holes

GeoTool → Simplify → Untrim Surface Purpose: to un-trim surfaces All Trim Edges – select wire or face from a face to recover the

raw surface

Inner Trim Edge Only – select wire from a face or faces to remove all the inner edges (all holes) on the face

Manual Selection Edges – select edge from a face to remove the selected edges by connecting or extending two neighboring edges on the face


GeoTool → Simplify → Fillet Surf. Remove

Purpose: to remove filleted faces from a solid surface Find – search for filleted surfaces

Apply – remove fillets by extending neighbor faces and trimming them


GeoTool → Simplify → Fillet Edge Remove

Purpose: to remove filleted edges from a shell surface Search – search for filleted edges

Apply – remove fillets by extending neighbor faces and trimming them


Raw face Face after filleted edges removed

GeoTool → Simplify → Edge Reshape Purpose: to reshape surface boundaries based on edge

tangents at two selected points


GeoTool → Simplify → Inner Region Purpose: to reshape surface of an inner region User can select a seed face in the inner region and to remove all

inner faces which locate inside the seed face and untrim the seed face in the loop region.


GeoTool → Simplify → Merge Same Surf Purpose: to search two faces which has the same

geometry surface from a shell, and finally merge them together


GeoTool → Measure Purpose: to measure the distance between two points, the

radius and angle of a circular arc, the normal of a plane, whether two circles are co-centered, whether two lines are parallel, etc... You can also show or hide the ID of any geometry object.

If Vertices/Edges/Faces/Shapes are checked, the label of each corresponding entity will be shown

If a geometry object is selected, its information will be listed

If two geometry objects are selected, the relationship between the objects will be evaluated

To check any two points' distance, check Measure Points' Distance.


GeoTool → Text Object Purpose: to create text object into curves or surface or solids

Click the font button to choose font, different font can greatly affect the meshing result


Arial Font

Times New Roman Font

Finite element mesh

LSPP Geometry Workshop 10 Repairing geometry


Workshop 10 Load iges model...

Launch a new session of LS-PrePost

Go to File->Open->IGES file (select /workshop10/raw_iges_data.igs)

Remove duplicated surfaces…

Go to GeoTol->Heal->Face, then click “Analysis”, the red surface will turn into grey, click “Apply”, this will delete the duplicated surface

Move edge to close the gap…

Go to GeoTol->Heal->Edge, select “Replace”, then click the edge on the green part as “Moved edge”, and select another edge on the blue part as “Dest edge” as shown in picture, then click “Apply”


Workshop 10 Stitch all surfaces…

Go to GeoTol->Stitch, check “All faces”, change the “Dis Tol:” to 0.15, uncheck “Group by part”, then click “Apply”

Remove inner holes…

Go to GeoTol->Heal->Hole, select “Inner”, then click “Analysis”, then click “Apply”


Workshop 10 Remove redundant vertices..

Go to GeoTol->Heal->Vertex, select “Remove”, then use the Area selection to select vertices as shown, then click “Apply”

Remove the outer hole..

Go to GeoTol->Simplify->Untrim, select “Manual Selection Edges”, select “Connect End Points”, then click one of the edge on hole as shown, then “Apply”, repeat the other half, and then “Apply”


Workshop 10 Repair notched edge…

Go to GeoTol->Simplify->Untrim, select “Manual Selection Edges”, select “Natural Extend Edges”, then click the edges on notch as shown, then “Apply”

Mesh the repaired geometry…

Go to Mesh->Auto Mesh, select “Size”, enter size as 0.8, select “visible” in the geometry selection interface, then click “Mesh”, and then click “Accept”


LSPP Geometry Workshop 11 Preparing geometry for meshing


Workshop 11 Load iges model...


Go to File->Open->IGES file (select /workshop10/Head_ansys.igs)

Problem:

Meshing this geometry without connecting all the surfaces will produce unconnected mesh which is not acceptable


Workshop 11 Trim large surfaces into smaller surfaces

Go to GeoTol->Trim, select “Mutual”, then go to the geometry selection interface and click “Visible”, and then click “Apply”

Stitch faces….

Go to GeoTol->Stitch, check “All faces”, check “Non-manifold mode”, uncheck “Group by part”, then click “Apply” Noted that one of the surface was not trimmed


Workshop 11 Fix faces that ware not trimmed and not stitiched…

Go to GeoTol->Trim, select “Standard”, turn on “Raw Trim Tool”, select the stiffener as trim tool, and select the surface as “Be Trimmed Entities”, as shown in the picture, then click “Apply”

Draw geometry in outline mode, see picture


Workshop 11 Fix faces that ware not trimmed and not stitiched…

Stay in GeoTol->Trim interface, select “Standard”, turn on “Raw trim tool”, in the Trim Tool, select one of the edge that is on the side wall of the box, and in the “Be Trimmed Entities”, select the 2 faces of the side wall, then click “Apply”, see picture for detail.

Repeat the same process for the wall on the opposite side


Workshop 11 Fix faces that were not trimmed and not stitiched…

Stay in GeoTol->Trim interface, select “Standard”, turn on “Raw trim tool”, in the trim tool, select one of the edge that is on the side wall of the box, and in the “Be trimmed entities”, select the face of the side wall, the click “Apply”, this will break the wall into 2 faces. Repeat the process for the opposite wall


Workshop 11 Mesh the final geometry…

Go to Mesh->Auto Mesh, select “Size”, enter 1.5 as element size, go to geometry selection interface and click “Visible”, then click “Mesh” in the meshing dialog, and then click “Accept”


LSPP Geometry Workshop 12 Create Bottle Geometry


Workshop 12 Create construction vertices...


Go to Curve → Point

Select Method: Parameters

Enter XYZ: 25,0,0

Click Apply

Enter XYZ: 25,7.5,0

Click Apply

Enter XYZ: 0,15,0

Click Apply

Enter XYZ: -25,7.5,0

Click Apply

Enter XYZ: -25,0,0

Click Apply

Click the Auto Center (AutCen) render button


Workshop 12 (continued...)

Create profile edges...

Go to Curve → Line

Select Method: Point/Point

Click the Selection List box

Pick vertices 1 and 2

Click Apply

Pick vertices 4 and 5

Click Apply

Go to Curve → Circular Arc

Select Method: 3 Points


Pick vertices 2, 3, and 4 (in that order)

Click Apply



Create a reference axis for reflection...

Go to Reference Geometry → Axis

Select Method: Two Points


Pick vertices 1 and 5 (in that order)

Click Apply

Reflect the profile edges...

Go to Geometry Tools → Transform

Select Transform Type: Reflect

Click in the Source Entity box

Pick all 3 edges

Select By Axis

Select Dir: Sel. Axis

Click in the Point/Axis/Plane box

Pick the reference axis

Activate Copy

Click Apply



Create a surface from the profile edges...

Go to Surface → Fill Plane

Select Method: By Edges


Click Visible in the General Selection interface

Click Apply



Create a solid (the Body) by extruding the profile surface...

Go to Solid → Extrude

Click the Face List box

Pick the surface

Enter End Distance: 70

Click Apply




Round the edges of the Body...

Go to Solid → Fillet

Click the Shape List box

Pick any face of the solid

Select Equal Radius

Enter Radius: 2.5

Activate Whole Shape

Click Apply


Workshop 12 (continued...) Create a reference coordinate system...

Go to Reference Geometry → Point

Select Method: Barycenter


Pick the top face (farthest from extruded edges)

Click Apply

Go to Reference Geometry → Axis

Select Method: Point to Plane


Pick the top face and the reference point

Click Apply

Go to Reference Geometry → Coordinate System

Select Method: Origin/Direction

Click the Origin box

Pick the reference point

Click the Z Dir box

Pick the reference axis, click Apply



Create a solid cylinder (the Neck)...

Go to Solid → Cylinder

Select Method: Parameters

Click the Coordinate Sys box

Pick the coordinate system

Enter Radius: 7.5

Enter End Height: 7

Enter End Angle: 360

Click Apply

Combine the Body and Neck (to form a Bottle)...

Go to Solid → Boolean

Select Method: Union

Click the Solid Shapes box

Pick the Body

Pick the Neck

Click Apply



Hollow out the Bottle...

Go to Solid → Thicken

Click the Solid Shape box

Pick the Bottle

Click the Remove Faces List box

Pick the top surface of the Neck

Enter Thickness: 0.6

Click Apply



Create some circles (to create Threads on Neck)...

Go to Curve → Circle

Select Method: Coordinate



Enter Radius: 7.9

Click Apply



Enter Radius: 7.2

Click Apply

Click the Wireframe Geometry (WirGeo) render button



Create helices from the circles...

Go to Curve → Helix

Select Method: Height and Loop

Click the Circle/Arc List box

Pick one of the circles

Enter Height: 7

Enter Loop Number: 3

Click Apply

Click the Circle/Arc List box

Pick the other circle

Click Apply



Loft the helices and extrude the surface...

Go to Surface → Loft

Click the Profile Shapes box

Pick both helices

Click Apply

Go to Solid → Extrude

Click the Face List box

Pick the lofted surface

Click the Direction List box

Pick the axis normal to the top Neck face (in the reference coordinate system)

Enter End Distance: 0.4

Click Apply



Remove redundant shapes...

Go to Geometry Tools → Management

In the Entity List box, select all items except the two solid entities

Click Delete


Click the Shaded Geometry With Edges (EdgGeo) render button


Documents

LSPP Geometry