NON-LINEAR AUTO-PARAMETRIC STABILITY LOSS OF A SLENDER STRUCTURE DUE TO RANDOM NON-STATIONARY SEISMIC EXCITATION
Slender structures exposed to a strong vertical component of an earthquake excitation are endangered by autoparametric resonance effect. This highly non-linear dynamic process caused heavy damages or collapses of towers,bridges and other structures in the past. In sub-critical linear regime vertical and horizontal response components are independent and therefore no horizontal response component is observed. If an amplitude of the vertical excitation in a structure foundation exceeds a certain limit, a vertical response component looses stability and dominant horizontal response components arise. This post-critical regime (auto-parametric resonance) follows from the non-linear interaction of vertical and horizontal response components and can lead to a failure of the structure. The seismic type broadband random non-stationary excitation can be particularly dangerous in this connection. The paper tries to bring a qualitative assessment of this process using three-DOF theoretical model respecting dynamic properties of the structure and its subsoil including internal viscosity.
dynamic stability auto-parametric response non-linear dynamics semi-trivial solution postcritical response.
J. N′aprstek C. Fischer
Institute of Theoretical and Applied Mechanics ASCR v.v.i., Prague, Czech Republic
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）