A study on performance evaluation of hybrid dampers

Abstract

In this study, the experimental performance evaluation of the hybrid damper with an innovative structure was performed as a preceding study to apply the self-centering braced frame to the structure. Hybrid dampers used a structural novel material with recovery and semi-permanent characteristics to recenter the displacement caused by external loads. Structural novel materials were used polyurethane and superelastic shape memory alloy(SSMA), which provide recentering capacity through recovery properties, and neodymium permanent magnets, which enhance energy dissipation through friction properties. SSMA could recover the displacement generated at room temperature due to shape memory effect and superelastic behavior, and initial compression was applied to polyurethane to give recovery. In order for each material to play a role appropriate for its purpose, the hybrid damper was designed so that SSMA was applied in tension, polyurethane in compression, and neodymium permanent magnet in friction. In addition, a structural experiment was conducted on the damper by setting the design variables to the initial compression of polyurethane and the presence or absence of neodymium permanent magnet. As a result of analyzing the maximum force, residual displacement, recentering force, and energy dissipation capacity for the behavior response derived from experiments on each model, the model that included all three new structural materials and applied the largest initial compression showed the best performance. Therefore, it is expected that the development of a self-centering braced frame will be possible if a hybrid damper is applied as a result of performance evaluation through structural experiment.