动力总成悬置系统模态解耦与复杂基础弹性振动特性研究

针对动力总成等振源机器多维振动耦合问题,建立动力总成悬置系统运动力学模型,求解动力总成六自由度固有频率及主要振动模态解耦条件,并应用于工程某重型货车动力总成悬置系统设计。针对工程中复杂基础弹性振动问题,通过有限元仿真获得复杂基础模态信息,代入振动能量传递方程,进而得到复杂弹性基础隔振系统振动能量传递特性。数值模拟结果表明:振动能量曲线在复杂基础共振频率附近出现显著且密集的共振峰,隔振效果在中高频段恶化,基础弹性特性在总体系统振动传输中起关键作用;基础刚性提高对系统隔振有利。所用方法对研究工程复杂弹性基础隔振系统振动问题具有重要实际意义。

A decoupling method of powertrain mounting systems and vibration characteristics analysis of complex flexible foundations

A dynamic model of a powertrain mounting system was derived to explore multi-dimensional coupling vibration of the powertrain.Then six degree-of-freedom natural frequencies were calculated and decoupling conditions of the most important vibration modal were confirmed.A powertrain mounting system of heavy truck was designed and verified.FEM and the power flow theory were combined to explore flexible vibration of complex foundations in engineering.Modal information of complex foundations can be obtained from FEM and taken into vibration power functions.Then vibration power transmitted in the vibration isolation system with complex flexible foundations can be obtained.The results show that obvious and dense peaks of vibration power appear because of foundation flexibility, isolation effect has deteriorated at middle and high frequencies.Foundation flexibility is essential to vibration transmission in the whole system.The increase of foundation rigidity is beneficial to vibration isolation.The new method is practically significant to explore flexible vibration isolation systems with complex foundations in engineering.