STOCHASTIC SENSITIVITY ANALYSIS OF NONLINEAR PRIMARY-SECONDARY STRUCTURAL SYSTEMS

A response and sensitivity analysis of the mean-square response of sec ondary systems attached to yielding primary structures is presented. T he main objective is to examine the effect of nonlinearity in the prim ary structural behaviour on the response characteristics and its sensi tivity to secondary systems in a stochastic environment. The procedure follows equivalent linearization with partitioning in order to allevi ate the dimensionality problem. Under white noise excitation, results show that yielding of the primary structure generally favours the seco ndary system response and its sensitivity, except in the tuning region in which amplification can take place due to the frequency shift of t he yielding primary structure. With regard to the placement problem of secondary systems, while position sensitivity varies significantly in the linear case, yielding of the primary structure tends to produce a smoothing effect, leading to a more uniform sensitivity behaviour.