Stochastic Simulation of Maximum Structural Response with Random Damping: Application to the Algerian Seismic Design Code

We present in this paper, the main results of a numerical investigation of the effect of critical damping uncertainties on the maximum response of systems with random damping. For this purpose, the excitation is defined by a specific target response spectrum. The critical damping coefficient is distributed according to the Lognormal probability density function with known mean and standard deviation. The Monte Carlo method is used to perform a second order analysis of the simulated response spectrum amplitudes. The applicability of the proposed methodology is illustrated using several target response spectra corresponding to real accelerogram records and design response spectra of The Algerian Earthquake Resistant Regulations (RPA 2003) associated respectively, with each of the four soil types: rock, firm, soft and very soft. The simulation results are then presented in terms of variations of the amplitudes of response spectra to illustrate quantitatively the effect of the uncertainty of the damping on the maximum structural response and conclusions of engineering importance are given.