Daneshjou - Prof.- IUST, Mech. Eng. Dept.
Talebitooti - PhD Student - IUST, Mech. Eng. Dept.
Nouri - PhD Student- IUST, Mech. Eng. Dept.
Ramezani - MS Student - IUST, Mech. Eng. Dept.

An exact solution of free harmonic wave propagation in a double-walled orthotropic cylindrical shell whose walls sandwich a layer of porous material is presented within the framework of the Sanders theory for anisotropy elasticity shells. The strongest component of the three waves in the porous layer is identified by applying the full method to a double flat panel of infinite extent with the same cross sectional structure. Using the most dominant wave component enables the porous layer to be represented as an equivalent fluid; therefore, the system is modeled as a shell with double walls sandwiching multiple layers of fluids. The Transmission Loss through the multi layered walls of the shell is obtained analytically by using the approximate method. Analytical results are presented for a variety of effective parameters and are compared with those obtained with the shell without porous material.

Transmission Losses, Porous Media, Orthotropic Double Walled Shell