Boundary Element Software Technology Corporation







Boundary Element Software Technology Corporation

GPBEST 7.0 Release

06/01/2002 -- BEST Corporation developers of GPBEST schedule the next release of GPBEST version 6.2 for July, 2000. Many new enhancements have been made and minor bug fixes applied refer to the following list for specifics:

1. General Enhancements

[New!]A new Eigenvalue solver has been implemented in GPBEST for use in free vibration and acoustic eigenfrequency analysis. The new eigenvalue extraction formulation is extremely accurate and allows the user to choose the number of eigenvalues and eigenvectors extracted.

Input of data in a cylindrical coordinate system is now available. The coordinate system is the basic cylindrical system that is defined with the origin at the origin of the global system, the Z-axis corresponding to the global Z-axis, and theta=0 along the positive global X-axis and measured counterclockwise. (The default is the global Cartesian system.) This cylindrical system is assumed for all input, including **GMR, **INTERFACE, **BCSET, and **BODY force input. See the COORdinate-system card under **CASE input for details.
The ability to define axisymmetric data in a Z-R coordinate system. For example, the coordinate system that is used by GPBEST for axisymmetric systems (R corresponding to X and Z corresponding to Y) is convenient for pressure vessels but very inconvenient for rotating structures (where Z corresponds to X and R corresponds to Y). See the COORdinate-system card under **CASE input for details.
Input of boundary conditions in any arbitrary local coordinate system that is unique to the current BCSET. There are two new options here:
The tangential directions in a LOCAl NORMAL system can now be defined.
A completely arbitrary local coordinate system can be defined. See the LOCAl card under **BCSET for details.
A uniform mechanical and thermal LOAD can now be applied to elements instead of traction and flux. See the LOAD card under **BCSET for details.
A TORQue-bc can now be directly applied to elements. See the TORQue-bc card under **BCSET for details. Since boundary conditions can now be defined with an arbitrary local coordinate system, torque can also be applied with tangential tractions. See the LOCAl card under **BCSET for details.
Mechanical (traction, load and torque) and thermal loading (flux and heat load) can now be applied on interface elements. See the INTErface card under **BCSET for details.
Prestress springs are now available. For both springs on the boundary and springs on an interface an initial spring deflection can be specified. See the SPRING cards under **INTERFACE and under **BCSET for details.
INCLude-file card now permits inclusion of external files in the GPBEST data file. See the INCLude-file card under **CASE input for details.

2. GPBEST Translators

Direct support for HYPERMESH, FEMAP, along with PATRAN and I-DEAS is now available.
Efficiency improvements have been achieved in both prebest and postbest leading to faster execution times of the translators.
Now there is only one prebest executable (80,000 dof) for all versions of GPBEST.
Element based data can now be output from the postbest translator for an extremely accurate display of contact pressure, normal force and frictional force.
Sampling surfaces and sampling points are now fully supported in prebest and postbest.
The accuracy of the interface detection algorithm in prebest has been improved. This includes interfaces in cyclic symmetry problems.
GEOMetry LINEAR capability has been included in prebest.
Anisotropic material properties are now supported for all preprocessor formats (i.e., PATRAN, I-DEAS, FEMAP and HYPERMESH) in prebest.

The postbest translator now warns the user if warning messages or fatal messages were encountered during the GPBEST run.

Various bug fixes have been made.

 3. Acoustics

Several enhancements, bug fixes and documentation were completed for acoustic analysis. Please refer to the following cards in **CASE input for details:
ACOUstic - documentation of auxiliary files for acoustic analysis
SACOustic - documentation of auxiliary files for structural-acoustic analysis
SWEEpfile - documentation of Sweep file for acoustic analysis
INPUt - documentation of NDFILE file for acoustic analysis

4. Thermal Analysis

Variable TIME STEP input for transient analysis is now available. This allows the user to use small time steps at the beginning of a transient run and then increase the time steps for efficiency as the diffusive process slows down. See the TIMEs STEP card under **CASE INPUT.
Three types of line elements are now supported for analysis of injection molding. Refer to the following **GMR cards:
LINE - general category of line elements was introduced which includes HOLE, RUNNer, and CLINe elements
HOLE - hole elements, used to model tubular exclusions in a material
RUNNer - runner elements are used to model tubular inclusions in a material
CLINe - cooling line elements are used to model fluid flowing through a tubular exclusion in a material
Display of Line Element results is now available. See the CONTour-plot card in **CASE input.

5. Other Improvements

The nodal coordinates can now be output in the neutral file with eight decimal place precision. This is critical, since a number of models are created in which one coordinate is 2 orders of magnitude larger than the other two. As a result, accuracy may be lost when calculating the displacement gradients for an element. This problem is now resolved.
In the material property section of the neutral file, there was no value for density nor the material angle. In the case of heat transfer, there were no properties at all, especially conductivity and specific heat. All of these have now been corrected.
In the interface section of the neutral file there were some missing data. There was nothing in the neutral file to indicate that an interface is a FIT or CONTact type of interface. Also, some of the interface modifiers, such as fit values or friction coefficient were not output. Finally, for a cyclic symmetry interface, the angle and direction vectors were incorrect (they were zero). All of these bugs have been corrected.
In the current version of the code, boundary conditions that are applied to nodes that are not source points cause a fatal error. Thus, it was quite painful to change a model from quadratic to linear variation if any of the boundary conditions were nodal based. Boundary conditions at non-source points are now simply ignored (a warning message is given).
Several other minor changes to GPBEST Neutral file format have been made for acoustic analysis.
A third card for the main header has been added which outputs informational, warning and fatal error messages.

For More Information Contact:

Boundary Element Software Technology Corporation
162 Golden Pheasant Drive, Getzville, New York, 14068
Tel: 716-639-1920
FAX: 716-639-1919





Copyright 2002 Boundary Element Software Technology Corporation