The Estimation of Random Response of a Coupled Cylindrical-Conical Shell System Using Statistical Energy Analysis

Abstract

A composite, coupled, thin cylindrical-conical shell system made of polyesterresin reinforced by uniformly distributed, chopped, E-glass is analyzed usingStatistical Energy Analysis. Response displacement estimate of the twosubsystems are obtained due the excitation of the cylinder by a broadband whitenoise of constant spectral density function. The paper is an attempt to study thevalidity of the SEA hypothesis as applied to coupled built-up structures. This iscarried out by the comparison of response estimates of the coupled system indifferent 1/3rd octave frequency bands with those obtained from Finite Elementmethod. The outcome of this work shows that SEA is a powerful tool for thevibration analysis of coupled systems at high frequencies when the number ofinteracting coupled resonant modes is high. Percentage error obtained from thecomparison of results drops sharply as one goes further in frequency. This paperrecommends that the user of SEA must always be aware of the uncertainty of theresults obtained. The uncertainty may arise from the improper selection ofsubsystems, coupling loss factors, and the number of interacting resonant modesof the coupled system.