Mid and high frequency vibration analysis of line connected uncertain composite structures by using modal impedance based statistical energy analysis procedure

Abstract

In this study, mid and high frequency vibration analysis of line connected composite structures having structural uncertainty obtained by mass variability is performed by using a procedure of modal impedance based statistical energy analysis (SEA). The procedure proposed here calculates finite system impedances in terms of modal information for each subsystem and uses these impedances in the prediction of SEA parameters. Modal information is extracted from finite element method by providing approximate physical boundary condition similarity of each subsystem with entire system. The procedure, on the contrary of classical SEA, considers not only driving point infinite impedances but also transfer point finite impedances to represent the total energy of the finite system more realistically. The procedure utilizes a dimension reducing principle based on point impedances to obtain line connection impedances. It is tested for line connected stiffened plate consisting of two isotropic beams and an eight layered symmetrically laminated composite plate having random mass variability. Its accuracy and capacity are presented by the results of finite element method based Monte Carlo simulations and classical SEA.