基于连接特性识别的子结构综合法

An Improved Substructure Synthesis Method Based on the Identification of Joint Characteristics

子结构综合法因其分块计算的特性,适用于由多单元组成的系统动特性的计算,但是对结构间连接的处理尚缺乏系统的分析和处理,而实际应用中,由于子结构之间的连接较为复杂,导致传统的机械导纳法计算结果准确性较低。考虑子结构综合法中连接单元特性对综合计算带来的影响,引入虚阻抗的概念,在结构综合计算中将连接单元对结构特性的影响以阻抗阵的形式引入进来,而连接单元的特性则根据整体单元及各个子单元的频响特性逆向推导所得,通过离散单元及弹性连续体单元模型验证考虑连接特性的综合方法在计算上的准确性,并将方法引入到铣刀动特性的预测中,通过设计实验验证了方法的可靠性。

Substructure synthesis method is widely used in the calculation of multi-unit system for its block calculation characteristics.However,there is a lack of systematic analysis for the joints of the substructures.Since the joints are usually complex and have a great influence on the dynamic performance of the whole system,they will reduce the accuracy of the computation results of the traditional mechanical admittance method.In this article,the concept of virtual impedance isproposed,the effect of the joint element between substructures of the system is introduced by using the virtual impendence matrix into the comprehensive calculation.The performance of the joint elements can be obtained by reciprocal formulation according to the frequency response characteristics of the system elements and the sub-elements.The computation accuracy of this method is verified by the models of discrete and elastic continuous elements.Finally,this method is applied to the prediction of dynamic characteristics of milling tools.It is concluded that the proposed method is more accurate than the traditional one by comparing the results with the measurement results.