THOPT
THOPT, Refopt, REFORMTOL, NTABPOINTS, TEMPMIN, TEMPMAX, --, ALGO
Specifies nonlinear transient thermal solution options.
RefoptMatrix reform option.
FULL
—
Use the full Newton-Raphson solution option (default). All subsequent input values are ignored.
QUASI
—
Use a selective reform solution option based on
REFORMTOL.REFORMTOLProperty change tolerance for Matrix Reformation (.05 default). The thermal matrices are reformed if the maximum material property change in an element (from the previous reform time) is greater than the reform tolerance. Valid only when
Refopt= QUASI.NTABPOINTSNumber of points in the fast material table (64 default). Valid only when
Refopt= QUASI.TEMPMINMinimum temperature for the fast material table. Defaults to the minimum temperature defined by the MPTEMP command for any material property defined. Valid only when
Refopt= QUASI.TEMPMAXMaximum temperature for the fast material table. Defaults to the maximum temperature defined by the MPTEMP command for any material property defined. Valid only when
Refopt= QUASI.- --
Reserved field.
ALGOSpecifies which solution algorithm to apply:
0
—
Multipass (default).
1
—
Iterative.
Valid only when
Refopt= QUASI.
Notes
The QUASI matrix reform option is supported by the ICCG, JCG, PCG, and sparse solvers only (EQSLV). The Quasi method is an approximation to the FULL method and will not be as accurate when the nonlinearity is strong. However, you can control the inaccuracy by using small time steps.
For Refopt = QUASI:
Results from a restart may be different than results from a single run because the stiffness matrices are always recreated in a restart run, but may or may not be in a single run (depending on the behavior resulting from the
REFORMTOLsetting). Additionally, results may differ between two single runs as well, if the matrices are reformed as a result of theREFORMTOLsetting.
For more information, see Solution Algorithms Used in Transient Thermal Analysis in the Thermal Analysis Guide.