Απόκριση συστημάτων με τμηματικά γραμμική ακαμψία υπο μεταβατικές διεγέρσεις

Abstract

This work investigates the response of a class of nonlinear elastic systems with piecewise linear characteristics, arising in mechanical and civil engineering applications. The study focuses on civil engineering applications related to the response of bridges equipped with elastomeric bearings for isolation of the structure, as well as seismic stoppers in order to resist strong earthquake base motions. In the present study these systems are represented by single degree of freedom structural models with piecewise linear elastic stiffness elements. In order to gain useful insight into the behavior of these systems, the behavior of single degree of freedom piecewise linear elastic mechanical models is first investigated under short duration sine pulse excitation. Then, the response of such system under long duration transient earthquake excitations is discussed. The analysis is concentrated on deterministic response spectra characteristics and the estimation of the sensitivity of these spectra to system and loading parameters such as stiffness ratio, gap sizes between deck structure and stoppers, excitation strength and frequency content. It is shown that the performance of such systems to transient excitation can be enhanced by optimally designing the system parameter values.