发动机机匣、支板系统结构动力分析

发展了在环向只能处理连续变量的常规有限条法。分析在环向由若干个离散分布的支板和支架支承的发动机机匣回转壳。各离散支板和支架回转壳刚度的贡献, 是通过支板和壳体连接处位移相等的变换, 将各支板的刚度阵叠加到回转壳的总体刚度阵上实现的。同时证明了位移在环向的Fourier级数展开式中, 只有n=0, n=1项对轴系的支承刚度有贡献。支板及支板附近的壳体的局部应力, 是由局部子结构空间板壳有限元分析得到, 该子结构的边界位移由整体的回转壳分析给出。算例表明, 本文提出的方法能有效地计算轴系的支承动刚度和壳体的局部应力。 

STRUCTURAL DYNAMIC ANALYSIS OF ENGINE CASE AND SUPPORTING SYSTEM

The normal finite strip method only capable of treating with continuous variables at circumferential direction is extended to dynamic analysis of engine case and supporting system.The engine case is simplified into a revolutionary shell supported at a shaft system and frame by means of several supporting plates and then is analysed by semi analytical method or the present finite strip method.The effects of the supporting plate on the revolutionary shell are considered by the way that the transformed stiffness matrices of the plates are added to the shell stiffness matrix at the conditions of displacement equality of contact points of the plates and the shell.The fact is proved that only n=0,n=1 words in Fourier expansion of circumferential displacements are devoted to the supporting stiffness of the shaft system.The local stresses near the plates and shell are obtained from substructure analysis using spatial finite element of plate and shell.The boundary displacements of the sabstructure are given by the revolutionary shell analysis.Numerical examples show that the presented method effectively enough to calculate the supporting stiffness of the shaft system and the local stresses of the shell.