模态分析技术在汽车结构动态修改中的应用

Application of the Modal Analysis in the Vehicle Structure Dynamic Modification

利用试验模态分析技术，建立了ＢＪ２１２汽车车架的动态数学模型。针对三种典型的道路状况（乡间土路、沥青道路和水泥混凝土道路），采用实测方法，获取了路面激励通过悬挂系统传递到车架结构的载荷谱。并以此为依据，结合车架结构的数学模型，利用力响应模拟分析技术，对车架结构在常用车速下的动态特性进行了模拟分析，并进行了结构动态修改，改善了其动态特性。

A dynamic mathematical model of BJ212 Jeep's chasiss was established by using the test modal analysis method in this paper. According to three different typical road, chasiss's response spectrum of road exciting that is transformed by spring system was acquired in road test. Combining the load spectrum with the dynamic model, the analysis of the struc ture's dynamic property under normaly vehicle speed was carried out using the FMS method. By modification of the structure, its dynamic property was improved.