基于整体车架模态分析的悬置支架优化设计研究

Mounting bracket optimization based on integral frame's modal analysis

针对某挖掘机发动机悬置系统振动放大问题,通过采用试验测试和计算机仿真的方法,评估并优化了其隔振性能。分析了对应的加速度频谱及该悬置系统在290 Hz等频段的共振问题,采用整车架模态分析方法实现了故障再现;根据仿真结果,对悬置支架和车架进行了优化设计,并对该优化方案进行了试验验证。研究结果表明:有问题的悬置3点振动传递率得到优化,达到了减振目标;悬置2点传递率出现略有升高的情况,而该位置的振动加速度峰值在优化后得到大幅降低;传递率升高是整体加速度略有增加引起的。

In order to resolve the vibration amplification issue in the powertrain mounting system of a given excavator, the vibration isolation performance was evaluated and optimized by the methods of experimental data analysis and computer simulation. The corresponding acceleration spectrum and resonance of the mounting system in 290 Hz and other frequency bands were analyzed and studied. The reason of the fault was captured by the whole frame modal analysis method. Meanwhile, the optimization scheme of the suspension bracket and frame suggested by the simulation results was verified by the experiment. The results show that the vibrational transmission rate of the #3 suspension gets optimized and reaches the target of decreasing the vibration. Although the transmission rate of the #2 suspension becomes worse slightly, the peak value of the vibrational acceleration at the #2 position is greatly reduced by the optimization. The increase of the transmission rate of the #2 suspension is due to the tiny raise of the overall acceleration.