Vibro-acoustic analysis of fiber metal laminate cylindrical shell using first order shear deformation theory

In this research, using analytical method, sound transmission loss in fiber metal laminate (FML) composite cylinder is studied. For this purpose, an infinitely long cylindrical shell composed of FML is subjected to an oblique plane wave. considering the effects of shear forces in the sound transmission loss, specifically at the higher frequencies, the FSDT theory is used to solve the governing equation of the motion. The equation of motion of the shell are obtained by D'Alembert principle. The equations are solved simultaneously using acoustic pressures, boundary conditions and infinite series that converged with a special algorithm, shell equations and acoustic relations. The values of sound transmission loss from numerical solution are validated with other researchers. This study shows that using FML cylinder instead of composite cylinder, the coincidence frequency increases 18 percent. Also in mass control region transmission loss increases 9 percent. It is demonstrated that with constant volume fraction of metal, locating aluminum lamina in farther distance from neutral axis, ring and coincidence frequency changes 11.4 and 18.7 respectively. In addition, results indicate that by increasing of 20 percent of metal volume fraction (MVF), in a specified frequency, transmission loss can be increased 28 percent.