Experimental study on the mechanical properties of looped fabric reinforced foam core sandwich composite

One of the well-known advantages of the sandwich construction is its high specific stiffness with lightweight. The property of withstanding the shearing, peeling, and flatwise tensile loading is an important factor of designing the sandwich structure. In the present study, the looped fabric reinforced foam core sandwich composite (U-cor) is proposed, and its flatwise tensile, peeling and shearing responses are investigated. Experiments are performed to study the mechanical behavior of the rigid polyurethane foam (RPUF) of different densities under tension, compression, and shear loading. Specimens of U-cor and the traditional 2D woven fabric reinforced foam sandwich composite (2DRFS) with thick and thin fiber yarns are investigated. Results show that the main failure mode of the 2DRFS is skin-core debonding. For the U-cor, the damage patterns are far more complicated. Besides breakage of foam, breakage of loop yarn may also occur. The interface performance of the U-cor is much better than that of the 2DRFS. Finite element analysis of U-cor under shearing load in warp direction is performed. The predicted shear strengths and failure modes are in good agreement with the experimental results.