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.
• AutoSUPORT 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.
• Nonzero 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
3point 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 postprocessing.
• 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 (XZ) 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 x8664 platforms
• The incore 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 "subgroups", 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 LP64 and
ILP64
• Free
field input improvements
SÍGUENOS
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