An Experiment on the Mechanical Properties of Metal Rubber Processed by Improved Processing Techniques and the Construction of Its Constitutive Relation

To figure out the performance of dampers made of metal rubber (MR) that are installed in bridge and frame shear wall structures to change the energy consumption mode of artifacts, experiments were performed on the MR material processed by improved processing techniques to test its compression and shear hysteresis properties in high-temperature environment, and discover the laws of the impact of factors such as the improved processing techniques and temperature on the compression and shear hysteresis of the material. At the same time, based on test curves and the strain hardening laws of the material, this paper employed the least square method to perform piecewise linear fitting on MR curves, and the corresponding strain hardening constitutive model was established and verified. The study suggests that, after processed by the improved processing techniques, the compression and shear hysteresis energy consumption performance of the MR test pieces is very stable, and the shear strength had been improved. As the temperature increases, the metal rubber consumes more vibrational energy, and the stiffness of MR vibration isolator increases as well; at a same temperature, as the strain amplitude and relative density increase, the vibrational energy consumed by the MR damping material increases accordingly. The simplified constitutive model constructed in the paper has a simple form, it can not only describe the strain hardening features of the material, but also conform to the test curves, therefore, it can facilitate the parameter design and the calculation of MR dampers. The research conclusions obtained in this paper can provide theoretical and experimental evidence for the processing, preparation, and application of MR dampers, and it is of very important theoretical significance and practical value.