Abstract: [Objective] In view of the main vibration isolation element on the car-rubber spring (the material is the traditional rubber), there are lots of disadvantages such as vibration isolation effect is not ideal, easy aging and sound insulation effect is not good, etc. Based on the theory of wood rubber, the rubber spring in the hydraulic suspension was put forward, and the structure modeling, software simulation and sample experiment were carried out in a commonly used semi active vehicle suspension, which can provide technical support for the application of the wood fiber material in automobile engine vibration reduction.[Method] In specific wood rubber spring material selection, the Korean pine cut from Xiaoxing'an Mountains was used, the density was 0.439 g·cm^-3 and moisture content was 12%-15%. Using the microns long filament cutting machine of forestry and mechanical engineering technology center in Northeast Forestry University, the thickness of wood fiber below 86 μm was cut and the average thickness reached about 50 μm. Then rubbing filaments and the manufacture product was applied on the main spring of semi active hydraulic mount device. The bond graph model and mathematical model of the semi-active hydraulic mount was established based on the bond graph theory. The simulation results obtained by Matlab/Simulink simulation tool were compared with the state equation of bond graph.[Result] In the low frequency range of 0-30 Hz, the dynamic stiffness of the hydraulic mount was highly consistent with the results of simulation and experiment, and the change trend of the damping lag angle was almost the same. In the high frequency range of 30-200 Hz, the dynamic stiffness of the hydraulic mount was similar to that of the simulation and the experimental results, however, the values of the damping lag angle were showed different.[Conclusion] 1) The application of wood rubber materials on the main spring of semi active hydraulic mount was completely feasible. The analysis of the vibration isolation characteristics of wood fiber rubber material was reliable, especially for the low frequency vibration isolation simulation. 2) Using bond graph method, the modeling and simulation of semi active hydraulic mount system of the main spring were feasible, and the simulation and test results of the model were good. 3) In the high frequency range, the simulation results were consistent with the experimental results, but some errors in the damping lag angle were found.

Key words: wood rubber, main spring, bond graph, semi-active, hydraulic mount