ABSTRACT

To investigate the effect of loading frequency to the mechanical behavior of SMAPRI, five loading frequencies, 0.05, 0.1, 0.5, 1.0 and 3.0 Hz, were considered during the uniaxial shear test. The shear strain amplitude was set as 20%, and the experimental results were shown in Figure 5. It is found that the shear stress-strain curves of SMAPRI is similar with high damping rubber bearings. However, the mechanical properties is stable to different exciting frequencies, which is also different from traditional rubber bearings. This property is helpful to analysis and evaluation the performance of SMAPRI during earthquakes. Additionally, the shear modulus increases with the nominal density of SMAPRI. The reason is that the number of micro spirals in unit volume of SMAPRI with high nominal density is larger than the low nominal density ones, and the porosity is also relatively low. The number of micro-spirals in the specimen also contributes to the energy dissipation ability of SMAPRI. It is noticed that the energy dissipated by the SMAPRI with nominal density of 0.25 is higher than the specimen with 0.23.