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Maxsurf 20.0 V8i ReadMe

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Maxsurf 20.0 V8iReadMe 19 August 2013

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 ................................................................................................................ 2Maxsurf Modeller .................................................................................................... 2

6483, 6748: Windage surface groups definition ............................................ 26720, 6753: Units dialog ................................................................................ 26730: New Markers features .......................................................................... 36727: Export render mesh .............................................................................. 4Bug fixes and minor changes ......................................................................... 5

Maxsurf Stability (Hydromax) ................................................................................. 56483, 6748: Windage surface groups definition ............................................ 5Bug fixes and minor changes ....................................................................... 12

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

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

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

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

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

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

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


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Software updates

The following section describes the changes that have been made to the variousprograms.

Maxsurf Modeller

6483, 6748: Windage surface groups definition

The windage profile may be displayed in Modeler by turning on "Windage Profile" in theDisplay | 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 andnot weights; that said when using kilopound-force, the masses are multiplied by standardacceleration due to gravity (9.80665m/s

2) 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 = 4.448221615Item weight = 2204.622622lbfItem weight = 2.204622622kip


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6730: New Markers features

Several new features have been added to the Markers which are designed to assist whenfitting 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 withthem (Markers table, or Markers properties); then select Measure Surface Error from theMarkers menu:

Measure the distance of the Markers from their associated Surfaces.

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


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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 thesurface. Enter the acceptable distance in the Markers table (the fill-down option can beconvenient 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 meshThe render mesh can now be exported in three new file formats *.obj, *.x and *.stl:


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Bug fixes and minor changes

6739: When porcupines are displayed a modeless dialog will now be displayed foradjusting 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 areasare defined and calculated have been added to the Maxsurf vessel model. These data maybe defined and edited in both Maxsurf Modeler and Maxsurf Stability via the WindageSurfaces dialog in hte Data menu.


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Windage Surfaces dialog (Data menu)

If no Windage groups are defined, then the older system for the calculation of windageand lateral projected underwater area is used. That is the hydrostatic sections areprojected into the transverse plane. The outer perimeter formed by joining the upper andlower limits of these projected sections is then used to calculate both the windage area ofthe hull and the underwater projected area. The zero-trim waterline at the current midshipdraft 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 themodel 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 surfaceswhich 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 underwaterlateral projected area. Individual surfaces may be included in multiple Windage Groups.Apart from the underwater group, Windage Groups have various factors associated withthem:

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. Thesurfaces 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 forTanks and Compartments.


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Windage Group definition and Surface selection

The color of the Windage Profile outline can be changed in the Colors dialog; theunderwater profile is shown using the "Immersed Sections" color.

Color selection

Wind direction


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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 doesnot matter.

Note that to improve performance, the projected windage contour uses a fairly coarsesurface mesh. This may result in the projected windage contour not exactlycorresponding with the surface edges, but the effect on projected area and center of areais negligible. Due to the calculation method used for the projected conoturs, it is possiblethat some visual artifacts may be present but again these have negligible effect onprojected area and center of area.

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

DisplayIn Maxsurf Stability, when the vessel is at the DWL, the normal windage profile view isshown and the wind profile groups may be modified. However once a Large AngleStability analysis has been performed, it is possible to select the windage profile used forany 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 windageprofile or calculating the actual projection of the heeled vessel. The option is specified inEdit | Preferences dialog. It should be noted that calculating the projected windageprofile at each heel angle can add significantly to the time required to complete theanalysis. For criteria evaluation, the underwater lateral projected area and center of areafor 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 beenselected in the Preferences dialog.


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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


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A new criterion wind heeling arm has been added that allows the definition of a verticalvelocity 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 foradditional area).

Wind heeling arm with velocity profile option

The velocity profile is defined by a series of horizontal strips parallel and above thewaterline. Each strip has a factors which is applied to the base velocity. This is done sothat 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 foreach 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"; afactor can be changed by typing ", factor"

Variable velocity profile

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


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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 definedheight zones and applying the velocity profile. This is done for all the windage groupswhose 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

groupgroupgrouptotal

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;

grouptotalF 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.


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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 aroom 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 surfaceoverlap. 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:


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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 theradial 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 ofthe speeds tested.


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Polar plots of selected result data

Ochi Hubble Spectrum

The Ochi Hubble two parameter spectrum has been added to the standard list of sea statespectrum. 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 representingthe sea (short period). A typical spectrum may look like this:


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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 panelanalysis can then be run on the oblique underwater shape. The Heel and Draft andTrim dialogs can be accessed from the Analysis menu. They are only available if theanalysis type is set to Panel Method. Once the heel and trim has been set the analysis

mesh will need to be recalculated.


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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 Havelocks

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 theresistance prediction algorithm in Rules for the Towing Survey of Barges andTugboats 2010 issued by Korean Register of Shipping and is suitable for box shapedvessels operating in displacement mode.


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Maxsurf VPP (Span)


Maxsurf Link (Hydrolink)


Maxsurf Fitting (Prefit)


Problem Reports

We greatly appreciate any bug reports or suggestions you may have. Please report anybugs or anomalies you find throughwww.bentley.com/serviceticketmanager.
http://www.bentley.com/serviceticketmanagerhttp://www.bentley.com/serviceticketmanagerhttp://www.bentley.com/serviceticketmanagerhttp://www.bentley.com/serviceticketmanager

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