SIMPLE ESTIMATION METHOD FOR CUMULATIVE PLASTIC DEFORMATION OF HYSTERESIS DAMPERS CONSIDERING HIGHER MODAL RESPONSES

In this paper, we propose a simple method to estimate the cumulative plastic deformation, η, of hysteretic dampers installed to a response control structure using multi-spring models equivalent to each mode of the structure. It is found that the ratio of η’s among the inelastic springs in the models, each of which corresponds to the dampers in each story, can be expressed by a simple function. The hysteresis energy of each spring can be estimated using the ratio, and the hysteresis energy of the dampers in each story can be estimated as the sum of those of the corresponding springs.