Dynamic response of stiffened laminated composite plate in thermal environment

Composite materials are increasingly used in aerospace and automobile sectors. These materials are characterized by high stiffness and light-weight in comparison to conventional structural materials. During high-speed maneuvering of these vehicles, associated composite structures are subjected to dynamic loadings and are often exposed to varying thermal environments. To ensure high load carrying capacity and to avoid thermal buckling, stiffened laminated composite plates are preferred in some important structural components, e.g., aircraft's fuselages, wings etc., than unstiffened laminated composite plates. For safe designing of these structures, it is thus necessary to investigate the dynamic behavior of stiffened laminated composite plates in thermal environment. In this paper, the dynamic response of stiffened laminated composite plates made of polyetheretherketone (PEEK) with intermediate modulus (IM7) carbon fibers in thermal environment has been investigated. Furthermore, development of a generalized finite element (FE) formulation using an 8-node isoparametric plate element employing first-order shear deformation theory (FSDT) has also been presented to analyze unstiffened and stiffened laminated composite plates in thermal environment. Detailed parametric study reveals that the dynamic deflection and the corresponding normal stress decrease with adding stiffener, and decreases further with increasing depth of the stiffener in thermal environment.