Bi-axial Seismic Behaviour of a Bridge Structure with a Shape Optimized Metallic Damper

Abstract

This study performs a structural analysis to determine seismic behaviour of bridge structures with optimally designed metallic damper absorbing earthquake energy. Since the metallic damper utilizes the plastic deformation of steel to reduce vibration of the structures, this optimized metallic damper can be more economic, reliable and sustainable than the conventional bridge dampers such as friction or viscous dampers. The considered earthquake loads applied to the structure is assumed to work on two-dimensional directions. Also, the shape optimization of metallic damper is purposed to perform ideally under those bi-axial earthquake excitations. The optimizing process is based on the calculation of dissipated energy by the damper through finite element analysis of ABAQUS and the SQP algorithm by MATLAB. The MATALB algorithm controls the alteration of the damper's shape to maximize the amount of energy dissipation under the constraint of total mass of the damper. To evaluate the effect of the developed metallic damper using this optimized shape, this study applied the damper into a three-span bridge model and conducted earthquake analysis through SAP2000.