摘要
复杂结构动态应力的精确计算是一个始终没有解决的问题,严重的影响了结构的疲劳寿命预估.采用位移模态叠加法的思路,将应力表示成模态应力的叠加形式,然后采用基于模态叠加理论的虚拟激励法,直接求得随机振动环境下动态应力的响应功率谱.这种方法的优点是避免了常规有限元法计算结构动态应力时必须对单元形函数求导的做法,并考虑了模态间的耦合效应.计算结果表明,采用本方法计算结构动态应力相较常规有限元方法将会得到更好的计算精度.
The accurate calculation of dynamic stress of complex structures is always a problem to be solved, which has serious influence on the prediction of structural fatigue life. In this paper, the node stress can be expressed as the superposition of modal stress based on the method of mode superposition. The power spectrum of dynamic stress can be directly obtained according to the pseudo -excitation method. In addition, the derivatizing element shape function which was necessary for calculating structure dynamic stress in the regular method can be ignored. Besides the method approved in this paper considered the coupling effects among modes, in order to improving the accuracy calculation of dynamic stress. Compared with conventional finite element method, the results of structural dynamic stress calculating by this method were more accurate.
出处
《哈尔滨商业大学学报（自然科学版）》
CAS
2014年第6期732-735,共4页
Journal of Harbin University of Commerce：Natural Sciences Edition
关键词
模态叠加法
虚拟激励法
应力响应功率谱
mode superposition method
pseudo - excitation method
power spectrum of stress response
