Statistical analysis of the inelastic response of shear structures subjected to earthquakes

Inelastic deformations of structures subjected to strong earthquakes are commonly accepted by Aseismic Codes; some discrepancies exist in the different procedures proposed to design a structure for which the ductility demand is to be limited within acceptable values. To have a better insight into the seismic behaviour of multi-degree-of-freedom structures beyond the elastic range, the dynamic elasto-plastic response of a ten-storey shear system under two sets of artificial and recorded accelerograms is studied considering different stiffness-strength distributions and constitutive laws. Statistics of the results are presented, demonstrating the dependence of the overall and storey ductility values and of their ratio on the characteristics of the structure and excitation