Cyclic behavior of carbon steel and austenitic stainless steel hollow laminated viscoelastomer-filled steel tube damper under unidirectional and bidirectional loadings

The hollow laminated viscoelastomer-filled steel tube damper (HLVSTD) is a metallic damper with stable working performance and excellent energy dissipation capability. It can exhibit equal mechanical performance in any single horizontal direction based on the geometric features of the circular shape. However, the impact of carbon steel tube material, stainless steel tube material and bidirectional loading on the mechanical behavior of HLVSTD remains unclear. The objective of this study is to analyze the mechanical performance of HLVSTD under bidirectional loading conditions using carbon steel tubes and austenitic stainless steel tubes, which are commonly utilized in China. Experimental tests were conducted using both unidirectional loading and bidirectional loading to comprehensively assess the performance. The results indicate that, under unidirectional and bidirectional loading, HLVSTDs made from both carbon steel and austenitic stainless steel tubes exhibit stable hysteresis curves. In comparison to the carbon steel tube HLVSTD, the counterpart with an austenitic stainless steel tube demonstrates higher equivalent stiffness, ultimate force, energy dissipation and low-cycle fatigue performance. Moreover, HLVSTDs under bidirectional loading exhibit a similar trend in mechanical performance compared to those under unidirectional loading. Regardless of whether the tube material is carbon steel or austenitic stainless steel, the cumulative displacement and cumulative energy under bidirectional loading were found to be twice as much as those observed under unidirectional loading, which demonstrates the excellent mechanical performance of HLVSTD under bidirectional loading.