This section includes a general set of simple tests to verify the design sensitivity analysis
(DSA) technique for stress/displacement continuum
elements for static steps. Geometrically linear and nonlinear tests are done for both total
and incremental DSA formulations. In addition, selected
problems also test static perturbation steps and frequency steps. A full range of design
parameters is used, including those related to sizing (for example, material properties,
thickness) and shape (that is, nodal coordinates). The results verified are primarily
displacement sensitivities for static steps and eigenvalue sensitivities for frequency
steps.