In-Plane Shear Characterization of Composite GFRP-Foam Sandwich Panels

Abstract

Shear walls, diaphragms, and shear web structures are generally subjected to in-plane shear loading. Only a small number of test data regarding the in-plane shear behavior of glass fiber–reinforced polymer (GFRP) sandwich structures are currently available. Using ASTM’s picture frame shear test, this work reports a systematic experimental approach coupled with both two-dimensional (2D) and three-dimensional (3D) digital image correlation (DIC) methods to characterize the failure modes of sandwich structures. Constituent materials such as plain foams, GFRP laminates, and GFRP-foam sandwich panels featuring different polyvinyl chloride (PVC) foam core densities and face sheet thicknesses were tested. The principal strain ratio measurement presented in this work was able to outline the interaction of failure modes. A simplified analytical model to assess the core in-plane shear load contribution was developed and validated. The core contribution was clear and should be taken into account for high-density foam materials and web-reinforced core designs. This research produced new in-plane shear data and a simplified design equation that will assist engineers in confidently sizing, designing, and predicting the in-plane shear capacity of sandwich structural members.