ABSTRACT
The effect of destructive earthquake ground motion represents a very important case of low cycle fatigue; thus, the analysis of plastic cycles due to earthquake is the basis to characterize the inelastic behaviour of the structures in seismic areas. In this paper, with reference to some significative ground motions and to the elastic-perfectly plastic model, the distribution of the plastic cycles is analyzed in terms of number of plastic cycles, maximum plastic deformation, mean value and standard deviation of the plastic amount of the other cycles. Different probability models (Normal, Lognormal, Exponential, Beta and Gamma) are used to interpolate the real distribution of plastic cycles, and, on the basis of the statistical test of Kolmogorov and Smirnov, are compared each to the other.
