Experimental and numerical study on the cyclic behavior of web dumbbell-shaped damper fabricated of low-yield-point steel

Current double-conical steel dampers, mainly made from low-carbon steel, stainless steel or high-strength steel, do not perform well in terms of fatigue, energy dissipation, and plastic deformation. To address these limitations, this study proposes a web dumbbell-shaped damper fabricated of LYP225 low-yield-point steel (LYP-WDP). This innovation aims to significantly improve the hysteretic behavior and fatigue performance of double-conical steel dampers. Given the limited experimental research on the hysteretic behavior of LYP-WDP under cyclic loading, this study conducts tests to evaluate its performance. Seven full-scale LYP-WDP specimens with different structural parameters were designed using LYP225 steel and subjected to low-cycle loading tests to assess their behavior under shear deformation. The effects of various design parameters on the performance of LYP-WDP were thoroughly analyzed. Finite element models of the specimens were created, and the simulation results were compared with experimental data. Additionally, formulas for calculating the elastic stiffness and yield strength of the LYP-WDP were proposed. The findings reveal that LYP-WDP has high ductility and stable energy dissipation capacity. The elastic stiffness and load-carrying capacity of LYP-WDP increase with the internal shrinkage ratio when the inner diameter and length of the energy dissipation segment are constant, while a negative correlation is found when the outer diameter and length are fixed. Increasing the length of the straight segment greatly enhances the energy dissipation capacity of LYP-WDP. The test results validate the accuracy of the proposed formulas and provide valuable insights for the design and application of LYP-WDP, marking a significant advancement in the field of damping technology.