抄録
This paper examined the destructiveness of strong ground motions for a single-degree-of freedom system with stable hysteresis, under forty-six accelerograms recorded in Japan and in the United States. An alternative index of the destructiveness named the "Cumulative Plastic Flow Intensity" calculated by the cumulative plastic flow response quantity, was introduced in terms of structural damage and earthquake-resistant capacity. The results obtained can be summerized as follows : (1) The ductility factor and the cumulative plastic flow response quantity, representing the destructiveness of ground motions, strongly depended on the natural frequency of the system. (2) The Cumulative Plastic Flow Intensity in case of the poly-linear hysteretic model compared with the bilinear hysteretic one showed a little overestimation. The contribution of the cumulative plastic flow quantity for the systems with longer period to the Cumulative Plastic Flow Intensity was remarkable. (3) The following simple experimental expression was obtained for the estimation of the Cumulative Plastic Flow Intensity (S_c) from the summation of square of ground motion acceleration (Power) ; S_c=a(Power)^c:c=1.0 or 1.5 in which a and c are the coefficients as described in the presented paper.
