某轻型客车地板振动发麻的试验及控制
Experimental and Control Study of the Vibration of a Light Bus’s Floor

针对某轻型客车高速时中部和后部地板振动脚感发麻的问题，首先，对车架和车身地板进行模态摸底测试和实车道路试验测试；其次，采用阶次跟踪法和频谱分析法分析出传动轴1阶扭转振动是地板振动的主要激励源，并利用模态分析法发现地板的第8阶局部模态频率与传动轴的1阶频率相接近，地板的局部共振是其振动发麻的主因；然后，从激励传递路径和优化地板模态分布两方面着手进行改进，利用虚拟样机技术优化传动轴橡胶支承的刚度，以最大幅度地减少传动轴振动向车内的传递，并采用有限元技术优化了地板的模态分布，使之避开了发动机和传动轴的工作频率范围；最后，通过样车试验验证了改进措施的有效性，解决了地板振动发麻的问题。
For the problem of vibration in the floor of a a light bus, the modal of its frame and interior body floor are measured, and the on-road vibration of the floor is tested. By performing order tracking and spectral analysis, it is found that the first order vibration of the transmission shaft is the main excitation source. Meanwhile, the 8th local mode of the floor is close to the first order frequency of the driveline in the modal analysis process, which would cause local resonance, and is the main factor of the violent vibration of the floor. Then we set out to make improvements in the vibration transmission path and modal distribution optimization. The nonlinear stiffness of the driveline rubber bearing is optimized by using virtual prototype technology to maximally reduce the transfer of vibration. For the resonance of the local floor, the finite element method is used to optimize the modal distribution of the floor, and the local modal avoids the working frequency range of the engine and the driveline. Finally, the effectiveness of the improvement measures is verified and the bus floor vibration is effectively controlled.