An innovative energy-dissipation angle bracket for CLT structures: Experimental tests and numerical analysis

Abstract

The connection system controls the behavior of the Cross-laminated timber (CLT) structures under horizontal loads. This paper introduced an innovative energy-dissipation angle bracket for CLT structures, which takes advantage of the soft-steel bracket and high-damping rubber to provide superior ductility and energy-dissipating capacity. Experimental tests under monotonic and reversed cyclic loading were performed to investigate the failure mechanism and mechanical properties of this energy-dissipation connector. After validating the detailed finite element models based on the test results, numerical parametric analysis was conducted to evaluate the influence of several parameters. The results show that the energy-dissipation angle bracket connector mainly exhibits three failure modes, including the rupture of dissipative ribs, local bearing failure of the base, and the debonding of the internal rubber. The ribs’ rupture is the dominant failure mode, especially under cyclic loading, after which the connector can still work integrally because of the rubber that is tightly bonded to the steel skeleton. All the tested connectors show high ductility and great energy-dissipating capacity, as indicated by the ductility larger than 9.5 and the equivalent viscous damping ratio within 9 %− 26 %. According to the numerical parametric analysis, the load-carrying capacity of the energy-dissipation angle bracket is positively correlated with the steel skeleton’s thickness and ultimate strength, and the adoption of the washer, while the rubber’s height has little impact on the load-carrying capacity. The outcomes of this study provide valuable references for subsequent improvement and potential applications of the innovative angle bracket for CLT structures.