摘要
提出固定界面模态综合法中子结构低阶主模态的截断方法。对子结构自由振动微分方程做移频处理,采用包含惯性力影响因素的子结构准静力模态进行坐标变换,降低了子结构低阶主模态对系统中频段模态的贡献,实现了子结构低阶主模态截断。采用该方法分析某白车身有限元模型160～190Hz的动态响应特性。结果表明:引入移频技术后,相比传统固定界面模态综合法,子结构保留的主模态数量从之前的1 836阶下降至297阶,计算时间减少27.7%,说明该方法能有效提高复杂结构中频段动态响应计算效率。
A method to cutoff substructure low order normal modes in component mode synthesis is proposed. Frequency shifting technique is introduced in substructure free vibration differential equation. Quasi-static constraint mode is taken into coordinate transformation and the contribution of substructure low order normal modes to system middle frequency modes is reduced,thus substructure low order normal modes truncation is achieved. This technique is used to compute dynamic characteristics of a body-in-white FEM mode in the frequency band of 160-190 Hz. The results show that compared with traditional component mode synthesis,which keeps 1 836 normal modes,this method only needs 297 normal modes and saves 27. 7% calculation time. It means frequency shifting technique can improve the computational efficiency for middle frequency band dynamic characteristics of complex structure.
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第1期29-34,共6页
Journal of Chongqing University
基金
973项目(2010CB736104)
汽车噪声振动和安全技术国家重点实验室开放基金资助项目(NVHSKL-201104)
关键词
模态综合法
模态截断
频率
动态特性
component mode synthesis
modal truncation
frequency
dynamic characteristics
作者简介
罗虹（1955-），男，重庆大学副教授，主要从事汽车系统动力学、汽车振动噪声控制研究，（E-mail）lhongcd@163．com。
