Hysteretic friction behavior of aluminum foam/polyurethane interpenetrating phase composites

In this study, the hysteretic friction behavior of aluminum foam/polyurethane interpenetrating phase composites (AF/PU composites) was experimentally investigated by different pre-compression, loading frequency and displacement amplitude. To describe this hysteretic response, the Bouc-Wen model was modified by introducing the accumulated stiffness, which was affected by the displacement amplitude. The maximum force, stiffness and damping ratio were measured in load-displacement hysteretic curves to evaluate the multi-phased hysteretic friction behavior. The experimental results illustrate that the hysteretic friction behavior is divided into three phases by the loading amplitude and is independent of the loading frequency, but the transition in each phase is greatly influenced by the enhanced pre-compression. The modified Bouc-Wen model is found to adequately capture the hysteretic friction response by comparisons with experimental data. All of the results demonstrate that the AF/PU composites have a good potential applied in friction dampers for improving the seismic performance of structures under the ground motion with different intensities.