PARAM, FLIPOK

Bulk Data Entry Allows tetrahedral elements to invert during shape optimization.

Parameter Values Description
FLIPOK <YES, NO>
YES
Severely distorted and possibly inverted elements will be accepted by OptiStruct. This is limited to first order Tetrahedral (CTETRA) and Triangular (CTRIA3) elements.
NO (Default)
Severely distorted elements will not be accepted by the solver, and the solution will be terminated with an error to avoid inaccurate results.

Comments

  1. PARAM, FLIPOK, YES can be introduced to force OptiStruct to run models with severely distorted and possibly inverted elements (CTETRA/CTRIA3). Since such models contain severely distorted and inverted elements, it is your responsibility to further validate the analysis or optimization results for accuracy, if this parameter is used.