Residual flexibility methods for decoupled analysis of integrated structural systems

Methods of dynamic analysis of large structural systems used in aerospace applications are examined. Full-system solutions are undesirable due to computational cost and logistics issues. Traditional substructuring methods effectively reduce system size through truncation of component modes, but still require an eigen-value analysis of the integrated system. A new method is discussed which utilizes residual flexibility to more accurately represent the motion of each component. Through the use of traditional displacement and force constraints on the substructures, interface equations of motion are developed which may be solved directly. Junction forces are used to drive the components at the interface, and the component equations of motion are solved at each time step, without need to form the full system equations of motion. The method allows easy examination of non-classically damped and nonlinear problems due to its formulation. Two sample problems illustrate the advantages of this method