This paper focuses on recent advances made in design, development, manufacturing, evaluation and modeling of load bearing fiber reinforced polymer (FRP) composite sandwich panel systems including tongue and groove joints. Several processes have been researched in collaboration with industry partners for production of composite panels, including: 1) pultrusion, 2) high temperature resin spread and infusion, 3) vacuum assisted resin transfer molding (VARTM), and 4) compression molding. The advantages and disadvantages of each process are discussed with emphasis on the high temperature resin infusion process. Composite laminates are characterized in terms of strength and stiffness under tension, bending, and shear in relation to longitudinal and transverse fiber orientations. Thermo-mechanical properties of the FRP composite sandwich panels including joint responses are presented in terms of: 1) the above different processes, 2) carbon fiber versus E-glass fiber, 3) vinyl ester resin versus epoxy resin, and 4) joint design and efficiency. The sandwich panels are evaluated at component and full scales under static four point bending loads and further analyzed using classical finite element models for their mechanical responses.

Fiber reinforced polymer composite; FRP; sandwich panel; tongue and groove joints; pultrusion; resin infusion; vacuum assisted resin transfer molding; VARTM; compression molding; thermo-mechanical properties; finite element modeling