Abstract: In order to study the vibration isolation analysis method for powertrain mounting system, a rigid flexible coupling multi-body dynamic model of a heavy truck is established. By comparing the simulation and test results of flexible frame and rigid frame vehicle model, it is found that the worst error is 8.9% and 25.1% respectively. The results show that the flexible frame vehicle model is closer to the test results and can be used to calculate the vibration isolation rate of powertrain. In order to simplify the analysis process, the three simplified methods is studied based on flexible coupling multi-body dynamic model. Compared with the test results, the maximum error of the simplified model is 12.3%, and the initial model is 5.34%. Therefore, simplified model can be used to calculate the vibration isolation rate of powertrain in the early stage of vehicle design. Meanwhile, it provides theoretical guidance for the calculation of powertrain vibration isolation rate and has important engineering application value.

Key words: Mounting system; Vibration isolation rate; Flexible frame; Rigid flexible coupling; Model simplification

摘要： 为研究动力总成悬置系统隔振分析方法，论文以某重卡为研究对象，建立整车刚柔耦合多 体动力学模型，并分别将柔性车架和刚性车架整车模型仿真结果与试验结果进行对比，最大误差 分别为 8.9%和 25.1%，表明柔性车架整车模型与试验结果更为接近，能够用于动力总成隔振率的 计算。为了简化分析过程，论文研究了基于柔性车架整车模型的 3 种简化方法，结果表明简化模 型隔振率与试验结果相差最大为 12.3%，与简化前相比隔振率相差最大为 5.34%，因此，在车辆设 计初期，没有实车及详细整车参数的条件下，利用简化后的模型可用于隔振率的仿真计算。该研 究为动力总成隔振率计算提供了一定的理论指导，具有重要的工程应用价值。

关键词: 悬置系统；隔振率；柔性车架；刚柔耦合；模型简化