Elasto-Plastic Model of a Seismic Energy–Dissipating Device

Abstract

A model of a seismic energy–dissipating device is formulated. The dissipating element is a U-shaped strip that undergoes a large rolling-bending deformation while confined between parallel rigid walls. The strip is divided into a number of rigid elements pivoted to one another in a chainlike fashion. A step-by-step solution is developed by considering small increments in the applied load. Increments in the bending moments arising at the pivots are expressed in terms of the changes in the angles between adjoining elements on the basis of corresponding changes in stresses acting on discrete strips into which the cross-section is divided. The stresses are calculated by means of a bilinear elasto-plastic model. The solution keeps track of the points at which contact forces with the constraining walls are developed. Examples are worked out resulting in hysteretic cycles that are compared with published experimental results.