Estimation of strains in composite cylindrical shells in a statistical energy analysis framework

Abstract

Broad band Acoustic excitation is one of the critical loading conditions for launch vehicle/spacecraft structures. Estimation of responses of such multimodal systems in a wide band dynamic environment is commonly performed using Statistical Energy Analysis (SEA). In SEA the strains are determined from known velocity responses. These relations are available for plate type structures but not reported for composite cylindrical shells. Empirical relations based on experiments only are reported for isotropic cylindrical shells. In this work, expressions for estimating the strains in the higher order modes of a composite cylindrical shell from its velocity responses are derived. It is seen that the strains estimated using the existing empirical relations of isotropic cylinders, with the elastic properties corresponding to the composite cylinder, will be in large error. Numerical simulations carried out using a finite element model are in good agreement with those determined using the relations presented in this work.