Performance Simulation Of Torsional Vibration Damper Based On The Parallel Of Positive And Negative Stiffness

The vehicle transmission is a torsional system of multiple degrees of freedom. Its torsional vibration is the main source of the vibration and noise in the vechile, and it has a great significance on the automotive noise, vibration and harshness quality. How to reduce the vibration of the vehicle transmission has always been a great problem, which people must face and solve in the vehicle transmission design. To solve this problem, the main solution is fixing a torsional vibration damper in the vehicle transmission.In order to overcome the disadvantage of th bete traditional passive damper of the inherent contradiction between torque capacity and elastic element stiffness, a semi-active torsional damper based on the parallel positive and negative stiffness has been studied in this paper. This torsional damper can reduce the vibration of the vehicle transmission with low stiffness, and it can keep great torque capacity at the same time. The performance of the torsional damper based on the parallel positive and negative stiffness has been researched in this whole paper through the combination of numerical simulation and experimental study.The mechanical model of the parallel mechanism of positive and negative stiffness has been established, and its stiffness characteristics were analyzed. This paper established the nonlinear dynamic model of the torsional damper based on the parallel positive and negative stiffness. This paper also established the dynamic model of the whole vehicle transmission, and this torsional damper was included as well. The simulation model of he whole vehicle transmission was obtained based on Matlab/Simulation software. The performance of the torsional damper based on the parallel positive and negative stiffness was analyzed with the simulation model. The influence of the new torsional damper to the natural vibration characteristics of the vehicle transmission was studied by calculating the inherent frequency. It can be proved that the new torsional damper is better than the traditional passive damper on reducing the vibration.The vibration damping performance of the new torsional damper under different working conditions was studied, including idling condition, driving condition and so on. This paper obtained different nonlinear simulation models because of the different working conditions. The results show that the new torsional damper can reduce the vibration of the vehicle transmission effectively under all kinds of working conditions. And it can keep great torque capacity at the same time. According to the results, the influence of engine torque and speed to the vibration damping performance of the new torsional damper was discussed and summarized.The optimization platform is set up through the Isight software integrate the nonlinear dynamic program and then solved with the DOE method. This paper finds out how the key parameters affect the vibration damping performance of the new torsional damper, and how they affect each other. The results provide reference for the improvement of the new torsional damper design.The vibration damping performance of the new torsional damper was tested through experiment. Time-domain and frequency-domain characteristics of the test results were analyzed. The results verified the correctness of the theory study.