NONLINEAR FINITE ELEMENT MODELING OF PRESTRESSED LEAD EXTRUSION DAMPERS

In the earthquake-resistant design of the structures, supplemental energy dissipative devices have increasingly been utilized for structural response control. The lead extrusion damper (LED) is one of the prominent versions of metallic dampers, as it dissipates high amounts of seismic energy by the extrusion of lead through the displacement of a bulged shaft. Its geometric properties, i.e., length and diameter of the tube, shaft, bulge, and lead, should be designed based on the target performance level of the host structural system. Thus, determining the LED's force-displacement relationship and seismic energy dissipation characteristics becomes essential for a proper design. In this study, the developed three-dimensional finite element modeling (FEM) strategy for the LED is examined through some literature experiments. The comprehensive three-dimensional model was utilized with the exact material characteristics determined through the coupon tests to increase the accuracy of predicting the LED's behavior. The numerical models were verified using the experimental results of the LEDs with different geometries adapted from the literature. The low relative differences between the numerically and experimentally obtained damper forces, i.e., 4.3% mean error, exhibited that the developed modeling strategy can accurately simulate the LED's hysteretic behavior. The consistency of the modeling strategy with different devices' behavior proved the versatility of the developed FEM. In addition, the effects of the different geometric properties on the LED's cyclic behavior were discussed numerically.