Maxsurfv20Readme

Maxsurf 20.0 V8i ReadMe

Page 1

Maxsurf 20.0 V8i ReadMe 19 August 2013

Release Note

This ReadMe file describes the changes in this release of Maxsurf 20 V8i suite of

software.

System Requirements:

32-bit versions will run on Windows XP/Vista/7, and

64-bit versions will run on Windows 7 64-bit.

Contents

Software updates ................................................................................................................ 2 Maxsurf Modeller .................................................................................................... 2

6483, 6748: Windage surface groups definition ............................................ 2 6720, 6753: Units dialog ................................................................................ 2 6730: New Markers features .......................................................................... 3 6727: Export render mesh .............................................................................. 4 Bug fixes and minor changes ......................................................................... 5

Maxsurf Stability (Hydromax) ................................................................................. 5 6483, 6748: Windage surface groups definition ............................................ 5 Bug fixes and minor changes ....................................................................... 12

Maxsurf Structure (Workshop) .............................................................................. 12 Plate clash detection ..................................................................................... 12 Bug fixes and minor changes ....................................................................... 13

Maxsurf Mtions (Seakeeper) .................................................................................. 13 Second Polar Graph view............................................................................. 13 Ochi Hubble Spectrum ................................................................................. 14 User defined heel and trim for panel method ............................................... 15 Bug fixes and minor changes ....................................................................... 16

Maxsurf Resistance (Hullspeed) ............................................................................ 16 Korean Register Barge Resistance ............................................................... 16 Bug fixes and minor changes ....................................................................... 17

Maxsurf VPP (Span) .............................................................................................. 17 Bug fixes and minor changes ....................................................................... 17

Maxsurf Link (Hydrolink) ...................................................................................... 17 Bug fixes and minor changes ....................................................................... 17

Maxsurf Fitting (Prefit) .......................................................................................... 17 Bug fixes and minor changes ....................................................................... 17

Problem Reports ..................................................................................................... 17


Page 2

Software updates

The following section describes the changes that have been made to the various

programs.

Maxsurf Modeller

6483, 6748: Windage surface groups definition

The windage profile may be displayed in Modeler by turning on "Windage Profile" in the

Display | Contours dialog (see section on Maxsurf Stability for further details):

6720, 6753: Units dialog

The units dialog has been updated so that masses may be displayed in kilopound-force

(kip). The dialog clarifies that values displayed in tones, kg, etc… are in fact mass and

not weights; that said when using kilopound-force, the masses are multiplied by standard

acceleration due to gravity (9.80665m/s2) to yield a weight. This option applies to all the

Maxsurf applications.

Option to display mass as a weight in kip.

For example:

Item mass = 1000 kg; g = 9.80665 m/s2

Item weight = 9806.65N; N per lbf = 0.45359237*9.80665 = 4.448221615

Item weight = 2204.622622lbf

Item weight = 2.204622622kip


Page 3

6730: New Markers features

Several new features have been added to the Markers which are designed to assist when

fitting surfaces to large Marker datasets (for example from laser scans).

The first is an option to color-code the Markers by their distance from their assigned

surface. Ensure that all the markers of interest have the correct surface associated with

them (Markers table, or Markers properties); then select Measure Surface Error from the

Markers menu:

Measure the distance of the Markers from their associated Surfaces.

Then in the Edit Preferences dialog, select “Show Marker Error with color gradient”


Page 4

Markers are now color-coded according to the distance from the surface (dark blue: closest; red: furthest away)

The second option is to hide markers that are below an acceptable distance from the

surface. Enter the acceptable distance in the Markers table (the fill-down option can be

convenient to do this). Then choose “Hide Acceptable Markers” from the Display |

Markers menu:

Hide Markers that are within an acceptable distance of their associated surface.

6727: Export render mesh

The render mesh can now be exported in three new file formats *.obj, *.x and *.stl:


Page 5

Bug fixes and minor changes

6739: When porcupines are displayed a modeless dialog will now be displayed for

adjusting the porcupine length.

7108: Symbol for knots has been changed from kts to kn across all apps

according to ISO standards.

6893: Users are warned when trying to bond edges that have grouped control

points.

6737: Cutting surfaces are now duplicated when a surface is duplicated.

7093: An issue where trimming gets lost when merging designs has been fixed.

7097: An issue where the Frame of Reference and design grid was not getting

scaled with the design using Quickstart has been fixed.

7052: An extruded linear surface has stiffness =1 (should be 2). Fixed.

7006: Crash in parametric transformation dialog if waterline length is 0m (i.e fully

submerged). Fixed.

Maxsurf Stability (Hydromax)

6483, 6748: Windage surface groups definition

A range of enhancements to the way the windage areas and underwater projected areas

are defined and calculated have been added to the Maxsurf vessel model. These data may

be defined and edited in both Maxsurf Modeler and Maxsurf Stability via the Windage

Surfaces dialog in hte Data menu.


Page 6

Windage Surfaces dialog (Data menu)

If no Windage groups are defined, then the older system for the calculation of windage

and lateral projected underwater area is used. That is the hydrostatic sections are

projected into the transverse plane. The outer perimeter formed by joining the upper and

lower limits of these projected sections is then used to calculate both the windage area of

the hull and the underwater projected area. The zero-trim waterline at the current midship

draft is used to determine which part of the projection is underwater and which part is

windage area. Because of these limitations, the effects of vessel trim and "holes" in the

model are not accounted for by this older method. The new method overcomes these

limitations as well as adding new features.

Windage Groups

The concept of a Windage Group has been added. This groups together model surfaces

which should be treated as a single object. There are always at least two Windage Groups

and the first one defines the surfaces that should be used to calculate the underwater

lateral projected area. Individual surfaces may be included in multiple Windage Groups.

Apart from the underwater group, Windage Groups have various factors associated with

them:

F_drag: winage drag factor; default value 1.0

F_shield: shielding factor; default value 0.0

F_user: a user-defined factor; default value 1.0

usershielddragtotal .0.1. FFFF

Windage Groups may be added and deleted with the respective buttons in the dialog. The

surfaces to be included in each group are defined in selected by double clicking in the

"Surfaces" cell in the table, in a similar manner to the selection of boundary surfaces for

Tanks and Compartments.


Page 7

Windage Group definition and Surface selection

The color of the Windage Profile outline can be changed in the Colors dialog; the

underwater profile is shown using the "Immersed Sections" color.

Color selection

Wind direction


Page 8

The Windage direction specifies the projection direction used for the surfaces: 90deg.

gives a projection in the lateral plane; 0deg. gives a direction in the longitudinal plane.

Angles between 0 and 180deg are allowed since the sign of the projection vector does

not matter.

Note that to improve performance, the projected windage contour uses a fairly coarse

surface mesh. This may result in the projected windage contour not exactly

corresponding with the surface edges, but the effect on projected area and center of area

is negligible. Due to the calculation method used for the projected conoturs, it is possible

that some visual artifacts may be present but again these have negligible effect on

projected area and center of area.

Windage projections viewed in profile at 90deg (upper) and 70deg (lower)

Display

In Maxsurf Stability, when the vessel is at the DWL, the normal windage profile view is

shown and the wind profile groups may be modified. However once a Large Angle

Stability analysis has been performed, it is possible to select the windage profile used for

any of the defined velocity profile wind heeling arms (see below for deails).

Display | Windage Profile dialog

Effect of heel

Maxsurf Stability has the option of using just the upright (zero heel) projected windage

profile or calculating the actual projection of the heeled vessel. The option is specified in

Edit | Preferences dialog. It should be noted that calculating the projected windage

profile at each heel angle can add significantly to the time required to complete the

analysis. For criteria evaluation, the underwater lateral projected area and center of area

for the upright (zero heel) vessel is always used; however the wind heeling moment will

use the actual inclined (including heel) projected windage area if this option has been

selected in the Preferences dialog.


Page 9

Upright or heeled/inclined projected windage area calculation preference

Windage profile calclated for the upright vessel and used for all heel angles

Windage profile calclated using heeled/inclined projected windage area method

Criteria: Velocity profile wind heeling arm


Page 10

A new criterion wind heeling arm has been added that allows the definition of a vertical

velocity to be specified. This heeling arm is always velocity-based (not pressure-based);

furthermore only the model-defined windage profile is used (there is no option for

additional area).

Wind heeling arm with velocity profile option

The velocity profile is defined by a series of horizontal strips parallel and above the

waterline. Each strip has a factors which is applied to the base velocity. This is done so

that the same velocity profile can easily be maintained for different base wind velocities.

To apply a uniform velocity profile (constant velocity at all heights) then simply specify

Uniform velocity profile

For a variable velocity profile simply specify the number of heights and the factor for

each height range: When entering the data for the velcity profile enter: "height , factor".

Heights must be in descending order. A height can he changed by typing "height"; a

factor can be changed by typing ", factor"

Variable velocity profile

When a variable velocity profile is selected for display, the different height zones are

displayed.


Page 11

Wind profile showing height zones defined in the selected variable wind velocity heeling arm

The wind heeling moment is calculated by dividing the windage profile in to the defined

height zones and applying the velocity profile. This is done for all the windage groups

whose contributions are then summed to give the total wind heeling moment. This is

divided by the vessel displacement to obtain the total wind heeling arm. Thus the wind

heeling arm, windarm , is given by:

heights groups

groupgroupgroup total

2

heightwind ).(...

)(cos.arm HhAFfv

g

a n

where:

a is a constant (typically half the density of air);

)(cos n defines the shape of the heeling arm (typically this would be 0.0 if the

calculation of the actual windage profile at each heel angle option has been selected);

.g is the weight-force of the vessel;

heights

... accounts for the summation over all the height intervals specified for the

velocity profile, with a base velocity of v and a factor at each height heightf ;

groups

... accounts for the summation over all the defined windage groups;

group totalF is the total factor for the windage group defined as

usershielddragtotal .0.1. FFFF

groupA is the area of the windage group

grouph is the vertical height of the center of area of the windage group

H is the height to be used for the assumed center of lateral resistance of the underwater

part of the hull.


Page 12


Tanks, compartments, non-buoyant volumes, etc. are now referred to collectively

as Rooms.

It is no longer necessary to select File | New when starting loadcases, room

definition etc. Simply start adding (Edit menu or Ctrl+A) rows.

6647: Fuel densities according to ISO 8217 have been added to the standard list of

fluid densities.

6815: The incorrect units for the Compact version of the cross-referenced heeling

arm criterion: ratio of GZ above heeling arm has been corrected to % (from m).

6731: Keypoint labels are now the same color as the keypoints (to facilitate

differentiation from Loadcase load items)

Some issues with the visibility of tanks in rendered mode have been fixed

Fixed issues with GHS imported models containing linked negative tanks, these

now remain negative components when changing the parent rooms to

compartments and back.

Improved the "extent of damage" command which determines whether or not a

room intersects a damage space; previously some false positives were generated.

The “Add Keypoint” menu item now has the correct wording.

6447: Autoballast, warn if attained CG does not match required CG.

5968: Section not forming correctly when Skin Thickness option is activated,

model specific. Fixed.

Maxsurf Structure (Workshop)

Plate clash detection

A warning dialog will now be displayed when two plates created on the same surface

overlap. Plate clash detection can be turned on and off from the preference dialog ( Edit

| Preferences…).

Strucutre will warn which plates are overlapped by the newly correctly plate:


Page 13


6933: Inclined frames can now be exported to Rhino file.

7058: Rhino files can be exported from Structure in two forms now. Firstly with all

parts as NURBS surfaces, secondly with all parts as trimeshes. To execute choose

File | Export | Rhinoceros 3dm file | NURBS Surfaces/Mesh Surfaces.

6715: String cutout not extending with stringer angle to frame. Fixed.

6959: Deducted frame not working correctly - model specific. Fixed.

Maxsurf Mtions (Seakeeper)

Second Polar Graph view

The original polar graph view has been renamed the Polar view, since in this view iso-

level contours of the selected result data are displayed on a polar plot with speed as the

radial axis. A new Polar Graph view has been added where the plot shows the same

selected result data plotted on the radial axis (against heading) with one curve for each of

the speeds tested.


Page 14

Polar plots of selected result data

Ochi Hubble Spectrum

The Ochi Hubble two parameter spectrum has been added to the standard list of sea state

spectrum. The Ochi Hubble spectrum is unique in that it allows for the generation of a

sea stat that has two peaks, one representing the swell (long period) and one representing

the sea (short period). A typical spectrum may look like this:


Page 15

User defined heel and trim for panel method

The model can now be placed at any attitude by using the trim and heel dialogs. A panel

analysis can then be run on the oblique underwater shape. The “Heel” and “Draft and

Trim” dialogs can be accessed from the Analysis menu. They are only available if the

analysis type is set to Panel Method. Once the heel and trim has been set the analysis

mesh will need to be recalculated.


Page 16


6918: User can now specify the upper and lower limits of the frequency range for

motions to be calculated at.

6825: A water depth can now be set for the Panel method analysis.

6695: Ocraflex Drift Force File export has been added to the File | Export menu.

6658: Ocraflex motions files can now be exported directly from Motions via the File

| Export menu.

6931: COM interface has been updated with Panel Method functionality.

6814: A problem which prevented calculation of added resistance using Havelock’s

method has been fixed.

6503: Angular velocity and accelerations are always given in rad/s and rad/s/s,

irrespective of user selected units for angle or frequency.

The maximum number of frequencies that can be calculated has been increased to

500.

Some issues with the data plotted in the Polar contour graph have been addressed.

7116: Roll phase was incorrect for Wave Excitation forces of a Panel method

analysis.

6977: Added resistance for panel method is now calculated (Havelock method).

6744: Stringers added on a surface in the section plane not rendering correctly.

Fixed.

6777: Cancelling a panel method analysis part way through was leaving temporary

files on disk. Fixed.

6837: Adding incorrect parameters to a section in the library was displaying a

blank dialog. Fixed.

Maxsurf Resistance (Hullspeed)

Korean Register Barge Resistance

A new barge resistance algorithm has been implemented. The method is based on the

resistance prediction algorithm in “Rules for the Towing Survey of Barges and

Tugboats” 2010 issued by Korean Register of Shipping and is suitable for box shaped

vessels operating in displacement mode.


Page 17


Maxsurf VPP (Span)


Maxsurf Link (Hydrolink)


Maxsurf Fitting (Prefit)


Problem Reports

We greatly appreciate any bug reports or suggestions you may have. Please report any

bugs or anomalies you find through www.bentley.com/serviceticketmanager .

http://www.bentley.com/serviceticketmanager

Documents

Maxsurfv20Readme