Abstract
A new principle, i.e. Finite Resonance Principle, in earthquake responses of inelastic systems is proposed and its effectiveness is verified. Finite Response Principle is induced from the well known average and standard spectra of visco-elastic systems which were calculated by Hounser, Takada, Okubo and Kuribayashi. This principle is composed of the following two fundamental ideas; (1) selective resonance (automatic syntony) of systems during earthquakes, (2) finiteness of the number of resonance waves. Assuming the equivalence of visco-elastic systems and inelastic systems, new and symple equations for the earthquake response analysis of structures with hysteretic restoring force functions are derived from Finite Resonance Principle. By means of this new method of earthquake response analysis, response deformation amplitudes and total energy inputs of inelastic systems subjected to earthquake excitations are able to be analyzed. As for perfectly elasto-plastic systems subjected to the El-Centro Earthquake, May 18.1940, analytical results are compared with the calculated results by numerical integration of equation of motion by Newmark and veletsos, Kato and Akiyama, Berg and Thomaides. The good agreement between them verifies the effectiveness of this Finite Resonance Principle.
