Constitutive relation expansion of large load metal rubber engine mount stress bivariate function relationship using the strain and strain rate

Abstract

Metal rubber materials were first used for vibration cushioning and noise protection applications in aviation equipment. With the recent developments in science and technology, metal rubber materials have been gradually implemented in Vehicle Vibration Suppressing. Metal rubber has significant advantages over ordinary rubber materials, in terms of its vibration damping in extreme environments. Along these lines, the objective of this work was to develop a mechanical model of metal rubber mount for mining vehicles, which can be used to predict the equivalent stress change of large load metal rubber mount in actual operation. Starting from the mechanical model of the mount and then expanding the macroscopic one-dimensional relationship of force and displacement to the binary relationship between the force and displacement and velocity, the microscopic one-dimensional relationship of stress and strain was expanded to the binary relationship between the stress and strain and strain rate. This work focused on the three-dimensional intrinsic structure model of stress, strain, and strain rate for metal rubber mounts. Moreover, the mechanical properties of the metal rubber mounts were explored in conjunction with the Mooney–Rivlin model, while the constitutive relationship of its stress, strain, and strain rate was deduced. The three-dimensional hysteresis curves were plotted by using software simulation analysis of the metal rubber mounts, and the metal rubber mounts hysteresis surface was also fitted. A combination of simulated and experimental data was used to test the accuracy of the proposed mechanical model of the metal rubber mount. From the acquired results, it was demonstrated that the errors of the relevant parameters (c10,c01, and c11) of the mechanical model of the metal rubber mount were about 10%. On top of that, the errors of the simulated stiffness values and the damping ratios of the metal rubber mount and the experimental stiffness values and damping ratios were within 10%. Excluding the interference of the metal rubber mount fabrication error, the proposed mechanical model met the mechanical analysis of the metal rubber mount with a large load and the mechanical model was accurate. The influence of the strain and strain rate on the stiffness and damping of the metal rubber mounts was also clarified, and the expansion method of the constitutive relationship of the metal rubber mount stress and strain was systematically explored. From the analysis of the metal rubber mounts’ mechanical properties, a reference basis for its vibration analysis and for the mechanical analysis of other nonlinear materials was provided.