title: Transmission loss of periodically stiffened laminate composite panels: shear deformation and in-plane interaction effects.
abstract: This paper investigates the transmission loss of symmetric and asymmetric laminate composite panels periodically reinforced by composite stiffeners. A comprehensive model based on periodic structure theory is developed. First order shear deformation theory is used and the coupling of the in-plane motion of the panel with its out-of-plane motion is taken into account. Stiffeners interact with the panel through three forces (two in-plane, one out-of-plane) and a torsion moment. Three types of cross sections are investigated for the composite stiffeners: I-shaped, C-shaped, and omega-shaped cross-sections. The model is validated numerically by comparison with the finite element/boundary element method. Experimental validations are also conducted. In both cases, excellent agreement is obtained. Numerical results show that the in-plane coupling effect is increased by increasing the panel thickness and the stiffener's eccentricity. The in-plane coupling effect is also found to increase with frequency.
authors.affiliation: GAUS, Department of Mechanical Engineering, Université de Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada. abderrazak.mejdi@usherbrooke.ca
authors.forename: Abderrazak
authors.initials: A
authors.lastname: Mejdi
authors.forename: Julien
authors.initials: J
authors.lastname: Legault
authors.forename: Noureddine
authors.initials: N
authors.lastname: Atalla