履歴塑性変形領域における1質点構造物の非定常ランダム応答について

Abstract

A new analytical technique is presented for the assesment of non-stationary random response of the one mass building structure with strong nonlinearity. This technique consists of the following four procedures; (1) deriving the Fokker-Planck equation for the probability density function, (2) transforming it to the equation for the characteristic function when the hysteretic characteristics are expressed by the signum type function of the response processes, (3) expanding the characteristic function by using the second order moment functions, (4) solving the simultaneous differential equations with respect to the moment functions obtained by comparing the coefficients of dummy variables in the expansion of the characteristic function. On account of some restrictions included in the above-mentioned procedures, such hysteretic characteristics as bi-linear or tri-linear ones are approximated by the positive deficiency characteristics, and non-stationary earthquake type excitations are confined to pseudo stationary processes expressed by the product of the white or nonwhite gaussian process and the deterministic function with respect to time. After investigating the propriety of this technique by a simulation technique and others, some numerical results relating to the hysteretic random response characteristic in non-stationary or transient state are studied.