基于改进剩余柔度矩阵的自由界面模态综合法

传统的自由界面模态综合法在求解过程中,模态截断后没有或没有很好地考虑剩余模态的影响,精度较差.这里提出了一种对传统自由界面法进行柔度矩阵改进的方法,这种方法恰当地考虑了模态截断后高价模态的影响,把模态截断后由低价模态柔度矩阵表示的高价模态改进后的柔度矩阵计入了子结构的运动方程,因而结构动态计算精度得以提高,并详细陈述了该改进柔度矩阵的推导过程.通过算例表明,与传统自由界面法相比,该方法明显提高了结构动态响应的求解精度,能满足工程需要,因此可以应用于大结构的动态分析中.

A Free-Interface Mode Synthesis Method Based on Improved Residual Flexibility Matrix

The purpose of this paper is to present a new improved method which has been developed from one of common free-interface mode synthesis methods.And in this improved method the residual flexibility matrix of reduced high-order modes,which are correctly expressed by the flexibility matrix of low-order modes,is improved to put into the equations of motion of a structure.That is to say those effects of residual high-order modes on the motion equations of a structure are considered correctly.In addition,how the improved residual flexibility matrix is derived is also presented in detail.Finally,the improved technique has been validated through an example:a beam with both ends built-in.It is shown that the improved free-interface method has a comparative higher precision in comparison with the common free-interface method known as the Hou technique.Therefore,this method can meet engineering requirements,and can be applied in large-scale structure systems for dynamic analysis.