Relation of Biaxial Nonlinear Response and Mechanical Properties of Structures

The effect of horizontal biaxial seismic input is not considered in the equivalent linearizing method, while the cases of investigation in terms of biaxial response displacement of structures are not sufficient to grasp the characteristics of biaxial elasto-plastic response comprehensively. The objective of this paper is to comprehend the relation between mechanical properties of structures and biaxial response displacement. With an analytical model of single-mass two degrees of freedom system, we conducted examination with parameters of mechanical properties; oblateness of yield surface, biaxial restoring force characteristics, and yield strength to uniaxial input. As a result, it was verified that response to biaxial input was often much greater than the response to uniaxial input, and oblateness of elastic response displacement to biaxial input was concerned with the characteristics of biaxial elasto-plastic response.