某乘用车动力总成悬置的NVH性能分析与优化

Analysis and Optimization of NVH Performance of Powertrain Mounting in a Passenger Vehicle

针对某乘用车在2档节气门全开工况下车内噪声过大的问题,应用LMS测试系统对汽车动力总成的悬置系统进行噪声振动测试和模态试验,通过对测试结果的分析,找到引发车内噪声过大的共振频率;应用有限元分析软件模拟后拉杆悬置实际工况和边界条件并仿真,通过对比分析测试试验和仿真分析结果,发现悬置隔振量小于20d B,不满足设计要求;通过在后拉杆悬置增加质量块与调整橡胶刚度,解决了后拉杆悬置共振与隔振量不足问题。测试结果表明,优化后的动力总成悬置系统明显降低了车内噪声与振动。

To solve the big interior noise problem under the wide open throttle condition in gear 2,the noise,vibration and modal test of the powertrain mounting system are tested by the LMS,that the resonance frequency causing the big interior noise is found after the test and analysis of the powertrain mounting system;the actual working condition and boundary condition of the rear rod mounting is simulated by finite element analysis software,comparing with the test analysis and simulation analysis results,the vibration is less than 20 d B,which doesn＇t meet the design requirements;the resonance and vibration isolation is solved by adding a mass at the side of the rear rod mounting and softening the rubber stiffness. It shows that the optimized powertrain mounting system significantly reduces the noise and vibration in the vehicle.