Colliding solids interactions of earthquake-induced nonlinear structural pounding under stochastic excitation

Abstract

A simplified analysis model of structural pounding, used in the study of the effects of earthquakes subjected to Gaussian white noise of relatively high intensity, filtered through a Kanai-Tajimi filter is proposed in this investigation. The required distance to avoid pounding is important in structural engineering. As a consequence of frictional contact phenomena, energy is dissipated and the state of a system can change slowly and rapidly, depending on the nature of the contact, continuous or impact condition. Buildings without enough separation often create structural pounding under seismic events. Other effects associated with friction in mechanical systems are the vibration and noise propagation of the system components, nonlinear systems behavior and wear. In this paper, we prove that because of the inherent stochastic nature of the applied earthquake loads or the uncertainty arising from randomness (non-smooth behavior), stochastic p-bifurcations occur at law noise intensities and disappear when increasing noise intensities. Because of the presence of both impact-friction events, p-bifurcations should be observed at weak noise intensities. P-bifurcation occurs and created instability that will increase pounding effects. Some relationship between impact-friction events appears: small noise intensity occurs when the time of friction (continuous) is greater than the impacting events, hence high probability density function (PDF). But if the noise intensity increases, the impact events are great (small friction) with weak PDF. But successive jump effects can create noisy system and great impact. The models stochastic processes of stationary probability density function (PDF) of the earthquake ground motion are set up. The demonstrative application examples which include friction in systems involving contact-impact events are illustrated in Central Africa, a part of Congo Stable Block.