Abstract：Thickness-diameter ratio, weakening ratio and height-diameter ratio are the main configuration parameters of lead-filled steel tube damper (LFSTD). To study the impacts of configuration parameters on the force-transfer mechanism, plastic-deformation distribution and energy-dissipation mechanism of LFSTD, 13 LFSTDs, with different configuration parameters, were designed and simulated by ABAQUS. The results suggest that (1) steel tube of LFSTD and lead core work cooperatively and dissipate energy together, while the force-transfer mechanism and energy-dissipation principle of LFSTD are clear. (2) The stress process of LFSTD can be divided into three phases including elastic phase, elastic-plastic phase and plastic phase. However, the elastic and elastic-plastic phases are short, and yielding displacement is small, so that LFSTD may go into yielding and energy dissipating even for 1mm displacement. (3) Thickness-diameter ratio, weakening ratio and height-diameter ratio may not remarkably affect the force-transfer mechanism of LFSTD. (4) Thickness-diameter ratio, weakening ratio and height-diameter ratio may significantly affect the plastic-deformation distribution of steel tube. To achieve the nice plastic-deformation distribution and the yielding energy dissipation concentrated in the middle part of LFSTD, the thickness-diameter ratio shall be as small as possible, the weakening ratio and height-diameter ratio shall be taken as 0.3~0.4 and 2.3~2.6, respectively. (5) During the energy dissipation process of LFSTD, lead core may yield and dissipate energy first with steel tube still remaining in the elastic state, and then steel tube goes into yielding and dissipates energy together with lead core. Once the energy dissipation of steel tube and lead core become stable, the energy dissipation of steel tube accounts for above 80% of total energy dissipation, while the energy dissipation of lead core may account for about 10%~20% of total energy dissipation.
