Research on High-Frequency Dynamic Models of Rubber Mounts with Second-Stage Isolation

The rubber mount is a key component of the electric vehicle powertrain mounting system, which can reduce the vibration of the powertrain transmitted to the vehicle body. The rubber mount with second-stage isolation means that a rubber vibration isolator is added to the metal bracket of the original rubber mount. Compared with the original rubber mount, the rubber mount with second-stage isolation has smaller dynamic stiffness and better vibration isolation performance in the high-frequency range. In this paper, the static stiffness of a rubber mount with second-stage isolation is tested, and the high-frequency dynamic characteristics of the rubber mount are calculated using the finite element simulation. According to its characteristics, an equivalent mechanical model including equivalent mass is established. Then, the fractional derivative model is used to express the complex stiffness element of the equivalent mechanical model, a high-frequency dynamic model of rubber mounts with second-stage isolation is established. At the same time, the identification method of the unknown parameters in the high-frequency dynamic model is given. The high-frequency dynamic model is used to calculate the high-frequency dynamic stiffness of a rubber mount with second-stage isolation. The results show that the high-frequency dynamic model can accurately calculate the high-frequency dynamic stiffness of the rubber mount with second-stage isolation. It can be applied to the high-frequency dynamic analysis of vibration systems containing rubber mounts with second-stage vibration isolation.