模态综合的子结构主模态截断方法  

Substructure Normal Modes Selection Method for Component Mode Synthesis

作　　者：李兴泉[1,2] 邓兆祥[1,3] 李传兵[1] 章竟成[3] 李英强[3] 

机构地区：[1]汽车噪声振动和安全技术国家重点实验室,重庆400039 [2]重庆长安铃木汽车有限公司,重庆401321 [3]重庆大学机械传动国家重点实验室,重庆400030

出　　处：《西南交通大学学报》2014年第1期173-178,共6页Journal of Southwest Jiaotong University

基　　金：国家"973"计划资助项目(2010CB736104)

摘　　要：为了减少固定界面模态综合方法中保留的子结构主模态数，分别采用频率截断和有效模态质量截断两种方法进行截断，分析两种方法的适用性，最终得到适合结构低频动态特性计算的主模态截断方法．计算结果表明：频率截断法保留的主模态不到有效质模态量截断法的1／2，采用2～3倍的最高关心频率进行主模态截断，能保证结构低频动态特性计算具有较高的精度，所保留的主模态，更能反应子结构在关心频率范围内系统振动的变形模式；有效模态质量法不能判断各子结构间主模态对系统动态特性作用的相对大小，这使小尺寸高刚度的子结构保留多余的模态，其计算效率较低．In order to reduce the normal mode number of retained substructures in the fixed interface component mode synthesis method, both frequency truncation and effective mode mass truncation methods were used for selection of component normal modes. By comparative analysis of the applicability of the two methods, the suitable normal mode truncation method for calculating structural low frequency dynamic characteristics was obtained. The computation results show that the normal modes of substructures retained by the frequency truncation method was 1/2 less than that by the effective mode mass truncation method. When computing complex structure low frequency vibration characteristics, setting the normal mode cutoff frequency to 2 - 3 times the upper frequency limit is sufficient to ensure high accuracy and efficiency, and the normal modes retained by the frequency truncation method can reflect better the substructure deformation caused by system low-frequency vibration. In contrast, the effective mode mass method cannot estimate the relative contribution of normal modes between substructures to the system low-frequency vibration characteristics; therefore, its truncation results may contain many redundant modes from substructures of small size and large stiffness.

关 键 词：模态综合 子结构 振动 频率 有效模态质量 

分 类 号：V261.3[航空宇航科学与技术—航空宇航制造工程]