Random response analysis

A two-element cantilever beam aligned along the $y$-axis is excited by prescribed ground accelerations in global degrees of freedom 1 and 6. B21 elements of unit length are used. A white noise power spectral density is used to describe the applied ground accelerations.

Since random response analysis is a modal-based procedure, a frequency step is required to obtain the mode shapes and natural frequencies of the system. Steps 2 and 3 test correlated and uncorrelated excitation between global degrees of freedom 1 and 6, respectively. Steps 4 and 5 test arbitrary load case numbering. Only the first two mode shapes have been used in the random response analysis steps, with a damping ratio of 0.01 for each mode.

A two-element cantilever beam aligned along the $x$-axis is excited by transverse distributed and concentrated loads. The concentrated loads are applied at the free end (magnitude of −1.0) and at the midnode (magnitude of −2.0). The distributed load acts on the element closest to the cantilevered end (magnitude of 4.0). B21 elements of unit length are used. Both the distributed load and the concentrated loads are described by white noise power spectral densities.

Since random response analysis is a modal-based procedure, a frequency step is required to obtain the mode shapes and natural frequencies of the system. Steps 2 and 3 test correlated and uncorrelated concentrated loads, respectively. Steps 4 and 5 test arbitrary load case numbering. Only the first two mode shapes have been used in the random response steps, with a damping ratio of 0.01 for each mode.