Implementation of natural frequency analysis and optimality criterion design. [computer technique for structural analysis]

Abstract A review of methods to compute the lower-frequency modes within a medium- to large-capacity computer design program indicates advantages for the simultaneous iteration method. For computer design, the computational advantages are further enhanced by more rapid convergence when using eigenvectors from prior design cycles. The optimality criterion design algorithms are summarized for the problem of minimum structural weight with constrained frequency and for the dual problem of constrained weight with maximum frequency. The capability to design for natural frequency requires only minor coding modifications within an existing computer program that can perform design for static loading. A simple sample application problem shows agreement with a known theoretical result. Another example shows effective results for a structure of practical complexity within reasonable computing times. A summary contains recommendations for continuing research.