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A Mesh Generator and Pre-Processor for
FEA and CFD Analysis

Release Notes for TrueGrid®
Version 2.3.3, October 20, 2009


1. There are now no limits on the number of bptol commands.

2. ETD command is now available for Fast Graphics mode.

3. There was a bug in Environment window related to the Global/Local button when it is at Pick mode.

4. There was a minor bug when the unifrm command and the intra-part BB command were combined on a single 2D region. In this case, an edge of the mesh that is logically intersecting the boundary of the region along the intra- part BB may be poorly interpolated. This has been fixed.

5. The character '$' with VERBATIM/ENDVERBATIM is not treated as a comment symbol anymore and will be written into the output.

6. An error in the LS-DYNA output which caused asterisks to be written out to the data file has been fixed.

7. Edges of the mesh formed in the Cylinder part attached to 3D curves or surface edges with quadratic elements using the cycorsy command to transform the local coordinate system could have a problem. This bug has been fixed.

8. There is a new volume in the VD command. It forms an ellipsoid. The command is:
VD vd_# EL x0 y0 z0 x_radius y_radius z_radius trans ;
where (x0,y0,z0) is the center of the ellipsoid and
where x_radius is the radius in the x-direction and
where y_radius is the radius in the y-direction and
where z_radius is the radius in the z-direction

As usual, a transformation is optional. The complement of the ellipsoid can also be used as a solid with:
VD vd_# CEL x0 y0 z0 x_radius y_radius z_radius trans ;

9. The EXODUSII output option now includes face (side) set, node set, and pressure surface names. For node and face sets, these are the names assigned to the sets in TrueGrid. Note that TrueGrid does not distinguish between upper and lower case and does not allow for spaces in the name. If you name a set in uppercase, it will appear in the EXODUSII input file as lower case.

Pressure surfaces are handled differently. If, for example, you use the load curve 123 in the definition of a pressure surface (using the pr or pri command), then the face set produced in the EXODUSII input file for this pressure surface will be assigned the name "Pressure Set 123".

Materials and element types have a third format for the Element Block names. It has the format:

Material n (order) element_type

where n is the material number, order is 1 for linear, 2 for quadratic, and element_type can be HEX, WEDGE, TETRA, SHELL, TRIANGLE, or BEAM.

For example:

Material 2 (1) HEX

10. A bug in NSETINFO has been fixed. It's been giving incorrect node information after merging.

11. The MTV command has been improved. It is now possible to assign a material of zero to a region or part in the part phase and then apply the MTV to change the material from zero to another material within that region. In the past, if a region of the mesh was assigned a material of zero, that region was not processed and no nodes or elements would be due to the region, even if the MTV command was issued.

Also in previous versions, if elements were not preserved because they were assigned a material of zero due to the MTV command, it was possible that the nodes that would have formed the element would be preserved, to float in space unconnected to any elements. This has been corrected in this version of TrueGrid. The material zero will no longer produce floating nodes.

This features also apply to SPH spherical elements (see SPARTICLE) for LS-DYNA.

12. TrueGrid now will catch memory allocation errors when internal memory requests cause integer overflow.

13. The information generated by the report command (and insufficient memory errors) has been updated to include memory usage for new commands and capabilities.

14. Two output bugs have been fixed in TOPAZ3D (version 2000) output. First, the conjugate gradient convergence tolerance, cgtol, is now written to card #2. Second, a blank line no longer follows the title card.

15. Warning messages related to the distribution of edge nodes have been improved so that they give the reduced indices of an edge that failed.

16. There are two new operators used to form transformations. They are:

SCV xn yn zn distance

DV x0 y0 z0 x1 y1 z1

The SCV operator results in a translation producing the same result as the V operator. In the case of SCV, a displacement vector is calculated in the specified direction from (xn,yn,zn) with a distance of dist.

The DV operator results in a translation producing the same result as the V operator. In the case of DV, a displacement vector is calculated from the difference vector (x1-x0,y1-y0,z1-z0).

There are many features that include these new operators. They are: LSYS, EL and CEL options of the VD command, 3D curves, surfaces, GCT, LCT, LEV, IGES and related commands, TR, TRI, BB, and TRBB.

17. Surface List window (COSURF) has been improved. Now it can list all the surfaces in display into the list of the window with a button click so that we can save them as a composite surface.

18. A new command in the merge phase can transform a part. If nodes have been merged, they are unmerged. After the part is transformed, a new merge command must be issued to remerge nodes. The command is:

TRPRT part_# trans ;

where a transformation is a product from left to right of the following operators

MX x_offset
MY y_offset
MZ z_offset
V x_offset y_offset z_offset
SCV x1 y1 z1 distance
DV x1 y1 z1 x2 y2 z2
RX theta
RY theta
RZ theta
RAXIS angle x0 y0 z0 xn yn zn
RXY
RYZ
RZX
TF origin x-axis y-axis
where each of the arguments consist of a coordinate type followed by coordinate information:
RT x y z (Cartesian coordinates)
CY rho theta z (cylindrical coordinates)
SP rho theta phi (spherical coordinates)
PT c.i (label of a labeled point from a 3D curve)
PT s.i.j (label of a labeled point from a surface)
FTF 1st_origin 1st_x-axis 1st_y-axis 2nd_origin 2nd_x-axis 2nd_y-axis
where each of the arguments consist of a coordinate type
followed by coordinate information:
RT x y z (Cartesian coordinates)
CY rho theta z (cylindrical coordinates)
SP rho theta phi (spherical coordinates)
PT c.i (label of a labeled point from a 3D curve)
PT s.i.j (label of a labeled point from a surface)
INV (invert the present transformation)
CSCA scale_factor
XSCA scale_factor
YSCA scale_factor
ZSCA scale_factor

19. The ESH and ESHI command has been extended to allow variable thickness in shell elements. The current command has the material followed by the constant thickness value. This form of the command remains valid for constant thickness shells. To form the variable thickness shells the constant thickness value is replaced with the VTH option flag followed by two surface definition numbers which specify the thickness envelope. I.e., to generate shell elements which have thickness defined by surfaces s1 and s2 the ESH command is

ESH i1 j1 k1 i2 j2 k2 material VTH s1 s2;

and the ESHI command is

ESHI i_list; j_list; k_list; material VTH s1 s2;

where the thickness of the shell at a node n is found by finding the distance in the direction normal to the shell elements on surfaces s1 and s2.

20. A bug in the fbc command for the Fluent output option was fixed. The default zone name for face sets was usually incorrect. Also, the 64 bit version of TrueGrid could not produce a valid FLUENT input file. This too has been corrected.

21. The KIVABC command has been extended for User Defined boundary conditions. In the part phase:

KIVABC region USERDEF n
where n is a positive interger less than 1000000. It should also be different from the reserved boundary condition numbers. In the merge phase:
KIVABC face_set_name USERDEF n where n is a positive interger less than 1000000. It should also be different from the reserved boundary condition numbers.

Up to 5 user defined boundary condition numbers can be used.

22. Warning messages of degenerate boundary faces for output have been improved. If there are more than 10 degenerate boundary faces while writing an output, TrueGrid will issue only 10 warning messages in addition to a summary message which tells the total number of degenerate faces.

23. Warning messages will now be issued when doing facial CONDITION or MLABS options. The messages consist of the number of degenerate faces encountered in specified condition option.

24. There was a drawing bug in Fast Gr. mode for quadratic elements. This occurred at DRAW after we issue a MERGE in Fast Gr. mode when we have both linear and quadratic elements in that order.

25. Format changes were made to the ICFEP output option.

26. Date infomation was not properly written to the ouput file for Windows systems. This bug has been fixed.