摘要
应用三维CAD软件建立车架的模型,通过接口输入动力分析软件,定义模型的材料、实常数以及约束情况等,对模型进行离散化,建立有限元模型,求解得到模型的前5阶模态参数。与利用试验模态法测试得到的前5阶模态参数吻合程度较好,两种方法均得到与发动机怠速时的激励频率25Hz很接近的一阶固有频率24.7Hz且振型为底板绕Y弯+墙板绕Z弯。为了避开此激励频率,利用修改后的有限元模型对车架进行结构修改,使得车架一阶固有频率与发动机怠速时的激励频率25Hz有了较大的偏移。
Three-dimension CAD model of a chassis was built.The model has been inputted into Dynamic analysis software through an interface program.After modified properly,the model was meshed.The anterior five modal parameters were calculated.Those parameters and prototype tests show that the two results were similar;and both methods found the modal was soleplate encircling Y axis ＋ wallboard encircling Z axis while the natural frequency was 25Hz that was engine’s sparking frequency working on idle speed.In order to be kept away from 25Hz,the chassis structure was modified using modified-finite element-model.As a result,the first nature frequency deflects the 25Hz greatly.
出处
《机械设计与制造》
北大核心
2010年第7期24-26,共3页
Machinery Design & Manufacture
