前置后驱汽车传动系统的扭振模态分析

摘要

A theoretical torsional vibration model for the drivetrain of a front-engine-and-rear-wheel-drive (FR) car was built. Torsional vibration modal frequencies were calculated by free vibration analysis and validated by comparing the re-sults with those of torsional vibration test of the car. Based on this model, the sensitivity of the torsional stiffness and mo-ment of inertia of different components to the drivetrain modal frequencies was analyzed. It is shown that the 3rd order mod-al frequency can be tuned by adjusting the torsional stiffness or moment of inertia of the wheels;the 4th order modal frequen-cy can be tuned by adjusting the torsional stiffness or moment of inertia of the wheel or the torsional stiffness of the half shaft;the 5th order modal frequency can be tuned by adjusting the torsional stiffness of the half shaft or the moment of iner-tia of the driving shaft.%针对某前置后驱车，建立了其传动系的扭振当量模型，通过自由振动计算分析获得了传动系的扭振模态，与整车传动系扭振测试结果对比，验证了计算的正确性。基于传动系扭振当量模型，分析了各部件扭转刚度及转动惯量对扭振模态的灵敏度：系统第3阶扭振模态可以通过改变轮胎扭转刚度或者转动惯量来调谐；第4阶扭振模态可以使用半轴的扭转刚度、轮胎的扭转刚度或转动惯量调谐；第5阶扭振模态的调谐参数为半轴扭转刚度和传动轴转动惯量。这些因素的分析可为车辆扭转振动特性的改善提供可参考的依据。