RESIDUAL FLEXIBILITY TEST METHOD FOR VERIFICATION OF CONSTRAINED STRUCTURAL MODELS

A method is described for deriving constrained modes and frequencies f rom a reduced model based on a subset of the free free modes plus the residual effects of neglected modes. The method involves a simple modi fication of the MacNeal and Rubin component mode representation to all ow development of a verified constrained (filed-base) structural model . Results for two spaceflight structures having translational boundary degrees of freedom show quick convergence of constrained modes using a measurable number of free-free modes plus the boundary partition of the residual flexibility matrix. This paper presents the free-free res idual flexibility approach as an alternative test/analysis method when fixed-base testing proves impractical.