Parameter

Values

Description

MAX_BUCK

<Integer > 0>

Default = 15

Controls maximum number of buckling eigenvalues to be considered for each buckling subcase in the optimization problem.

Can only exist if GBUCK exists.

Only up to MAX_BUCK eigenvalues are considered for each buckling subcase.

If the user-defined MAX_BUCK is less than 15 when auto screening is turned on, MAX_BUCK will be reset to 15. If more buckling modes need to be involved for a problem, explicitly specify MAX_BUCK (MAX_BUCK>15). To reduce the computational cost, OptiStruct automatically and dynamically adjusts the upper bound of the eigenvalue range on the EIGRL card for each buckling subcase at each iteration and only the eigenvalues that are possibly retained in the optimization would be calculated.