NX NASTRAN V6.0 ofrece las siguientes mejoras y novedades más importantes:

NX NASTRAN V6.0 Timeline

 Dynamics ...
The sparse data recovery capability introduced in NX Nastran 5.0 now includes SPC forces, MPC forces, Grid point forces/stresses/strains, and ASET/OSET definitions.
Auto-SUPORT is now available to automatically support any rigid body motions or massless mechanisms in solution sequences 103 (with residual vectors), 108, 109, 110 (with residual vectors), 111, 112, 145, and 146.
Non-zero initial conditions are supported for modal transient response.
An improved results recovery for constraint mode method of enforced motion has been created.
The absolute enforced motion method can now optionally include a coupled modal viscous damping term for increased accuracy.
Subcase support is now available for SDAMPING, TFL, K2PP, M2PP, and B2PP.
Damping can now be included when you use the ADAMSMNF case control command to write an ADAMS modal neutral file (MNF) directly from a SOL103 analysis.
The method of differentiation excitations has been updated to use a 3-point central differencing method.

 Linear Contact ...
The parameter NCHG on the BCTPARM bulk data entry determines the number of active contact elements allowed for convergence. Now NCHG can optionally be entered as the percentage of active contact elements.
The new PENTYP parameter on the BCTPARM bulk data entry allows the contact stiffness to be entered as a spring rate, which is a more explicit way of entering contact stiffness.
Under certain conditions, all of the contact elements could become inactive and may lead to singularities. The new parameter CSTRAT has been created to help avoid this condition by reducing the likelihood of all contact elements becoming inactive.
When contact is used, a CGAP element normal and transverse stiffness now uses the KA and KT values (if defined) respectively on the PGAP bulk entry.
The initial and final separation distances between the source and target regions can now be stored for post-processing.
The BCRESULTS case control command can now be assigned to a predefined SET ID to limit contact results output.

 Glue ...
The BGPARM bulk data entry has the new parameters, PENN and PENT, to define the normal and transverse glue stiffness independent of each other.
The new PENTYP parameter on the BGPARM bulk data entry allows the glue stiffness to be entered as a spring rate, which is a more explicit way of entering glue stiffness. For a SOL 153 heat transfer analysis, conductance can be varied in an analogous manner.

 Optimization ...
Ability to optimize for more than one frequency response subcase when the subcases use different boundary conditions.
Ability to optimize for more than one frequency response subcase when the subcases use different frequency sets.
Ability to automatically insert into a DRESP2 or DRESP3 response more than one frequency function value when the response is automatically generated for all values of a frequency set.
The new DRSPAN capability allows you to combine DRESP1 type responses from different subcases in a DRESP2 or DRESP3 type response.
Integrated DRESP1 responses, such as AVG, SUM, SSQ, are now available for element type responses as well, such as frequency stress response.
The DRESP3 capability, which became available in NX Nastran 5.1, has been updated for the new capabilities of version 6.
Some previously existing restrictions have been removed when using random loads in frequency response based optimization.

 Elements ...
The CWELD element now allows you to weld patches of elements, rather than just single elements.
The new CFAST element is similar to the CWELD element, except the CFAST stiffness is entered directly while the CWELD uses a weld of specified diameter.
Four new axisymmetric elements, the CTRAX3, CQUADX4, CTRAX6, and the CQUADX8 elements, will allow axisymmetric elements defined in a common coordinate system (X-Z) to be used across all solution sequences.
The RBE3 element now includes the coefficient of thermal expansion.

 Numerical Performance ...
Improved performance for Windows64 and Linux x86-64 platforms
The in-core FRRD1 Iterative Solver has been added to reduce possible huge I/O cost for modal frequency responses with a large number of modes.
The TAUCS sparse solver has been added for SOL 101.

 SOL 601/701 Advanced Nonlinear ...
Four new axisymmetric elements, the CTRAX3, CQUADX4, CTRAX6, and the CQUADX8 elements.
2D contact has been created, and is supported with the new axisymmetric elements, CQUADX4, CQUADX8, CTRAX3, CTRAX6.
An option to use a shell element coating on solid elements for the purpose of defining a 3D contact region is now available.
Previously, SOL 601 supported thermal expansion coefficients on orthotropic materials for the calculation of thermal loads only if the material was temperature dependent. This restriction has been removed in NX Nastran 6.
The MATT8 bulk entry, which is used to define orthotropic temperature dependency, is now supported in SOL 601.
The parameter NSUBGRP on the NXSTRAT bulk data entry controls the number of elements, or "sub-groups", which get processed at the same time in solution 601/701 operations. For example, NSUBGRP is used when building the element stiffness matrix.
Now write nonlinear stress/strain results for the CTRIA6 and CQUAD8 elements to the nonlinear datablock, OESNLXR. Also corner stress/strain results for CQUAD4 are also output.
The SPCFORCES output now supports set n can to limit the output to specific grids.
The output log file now contains summary solution convergence information for each time step where previously this information was only written to the .f06. Now the log file can be used to monitor solution convergence and progress.
The algorithm to evaluate beam element convergence between nonlinear iterations has been improved. As a result, models with beam elements should have an easier time converging.
By default, solution 601/701 memory allocation uses the value of the NX Nastran memory keyword. A new environment variable, NXNA_MEMORY, has been created in this release to optionally override this value (for SOL601/701 only). The variable should be defined in MB (megabytes).

 Other Improvements ...
Virtual mass performance improvements with PARAM, VMOPT, 2 option
External superelement control improvements with EXTSEOUT case control
Acoustic improvements with extensions to ACMODL entries
Automated OP2 file conversions for INPUTT2 between different Endian types and LP-64 and ILP-64
Free field input improvements

SÍGUENOS EN: Blog de "FEMAP y NX Nastran" en WordPress

Ir a la Página de Inicio

Productos | Soporte | Consultoría | Cursos | Universidad | Libros | Enlaces

Copyright © 2001 Ibérica de Ingeniería, Simulación y Análisis, S.L. -- http://www.iberisa.com --