Determination of Nonlinear Stiffness Coefficients for Finite Element Models with Application to the Random Vibration Problem
نویسنده
چکیده
In this paper, a method for obtaining nonlinear sti ness coe cients in modal coordinates for geometrically nonlinear nite-element models is developed. The method requires application of a nite-element program with a geometrically nonlinear static capability. The MSC/NASTRAN code is employed for this purpose. The equations of motion of a MDOF system are formulated in modal coordinates. A set of linear eigenvectors is used to approximate the solution of the nonlinear problem. The random vibration problem of the MDOF nonlinear system is then considered. The solutions obtained by application of two di erent versions of a stochastic linearization technique are compared with linear and exact (analytical) solutions in terms of root-mean-square (RMS) displacements and strains for a beam structure. NRC Postdoctoral Research Associate
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