Parameter

Values

Description

GBUCK

<YES, NO, 1 or 0>

Default = 0

Controls global buckling constraint.

Use 0 or NO, or omit this parameter for no global buckling constraint.

Use 1 or YES to activate global buckling constraint.

When activated, the global buckling constraint affects those subcases in which buckling eigenvalues (LAMA) are constrained. For these subcases, when this parameter is activated, only a single buckling mode needs to be constrained with a lower bound. The GBUCK parameter will then ensure that all buckling eigenvalues that are less than or equal to the lower bound defined in this constraint will be considered within the optimization problem.

More than one buckling eigenvalue constraint (or if the single constraint is not a lower bound) in any buckling subcase will cause termination with an error.

The MAX_BUCK parameter on the DOPTPRM card controls the maximum number of buckling modes for each subcase that are considered in the optimization. The EIGRL card referenced in the buckling subcase controls the number of modes calculated at each iteration.