A NUMERICAL INVESTIGATION ON THE RATE DEPENDENCE OF LEAD EXTRUSION DAMPERS

Lead extrusion damper is a highly effective energy dissipation device widely used in seismic mitigation systems. By forcing lead to flow through a restricted orifice formed by a bulged shaft at its core, this damper provides high energy dissipation capacity while maintaining a compact design. In the literature studies, some argue that the lead extrusion dampers are rate-dependent, while others suggest that the effects of loading rates are negligible. This study investigates the rate-dependent behavior of lead extrusion dampers through a set of finite element analyses conducted in ABAQUS software. An experimentally validated numerical model simulates damper performance under various loading rates. The effects of varying loading rates on the damper force and energy dissipation capacity are systematically evaluated. After discussing the success of some velocity models suggested in the literature, further refinements are proposed to enhance their precision.