Abstract:The residual dynamic flexibility, a new definition of the inertia relief attachment mode is proposed. The free-interface component mode synthesis method based on the residual dynamic flexibility can compensate for high-order truncate modes and it’s easy for experimental measurements. The approximated representations of residual mass and residual stiffness are deduced by partly ignoring the dynamic effects of the truncated modes. This method is used to set up the dynamic model of the full structure by coupling experimental model of component A and finite element model of component B. The problem of spatial incompleteness is solved by estimating the rotation mode shapes using a numerical differentiation method. Finally, numerical examples have demonstrated the validity and efficiency of proposed method.