A method is presented to analyze the dynamic behavior of a structural system consisting of a main structure and strongly coupled, multiply connected substructures. Lagrange's equations are used to develop a characteristic equation for connected substructures in terms of substructure impedances and mobilities. Then, a frequency window method is used to reduce the complexity of the problem by a decomposition of the impedance and mobility functions into dominant and high-order rational expressions. From the resuce problem, simple expressions for the modal properties are developed using matrix algebraic methods, which provide insight into the resonance characteristics of the connected substructures. Higher-order terms, which become significant for strongly coupled substructures, are included in the eigenvalue analysis by using an iterative procedure. It is shown that the frequency window method developed in this paper, used as a numerical scheme, produces results which converge to exact results after only a few iterations.
ASJC Scopus subject areas
- Mechanical Engineering