Efficient computation of nonlinear transient structural synthesis for seismic isolation

Abstract

A method of structural synthesis is presented using a recursive computational process. A structure can be modeled entirely linearly, with localized nonlinearities included as synthesized forces. The method allows retention of only the degrees of freedom (DOF) of interest, including, at a minimum, the DOF at which nonlinearities are applied. The method is illustrated using an n-degree of freedom finite element model of a simple structure. The method is shown to adjust the response of the system based on addition of a nonlinear base isolator. Finally, the method is compared to MATLAB's ODE45 function as a measure of accuracy and efficiency. The method is theoretically exact, and results in order of magnitude decreases in computational time for modification analysis.