Shear Strength Analysis of Sandwich Composite Cores Stitched with Natural Fibers

Abstract

A sandwich panel with a polyurethane rigid foam core is a composite structure consisting of a core layer sandwiched by fiber-reinforced layers, which are generally made of glass fiber. Natural fibers are attracting interest as an environmentally friendly alternative to foam reinforcement. In this research, an analysis was carried out on the shear strength of sandwich composite cores stitched with natural fibers.  The specimen is a sandwich composite with polyurethane foam as the composite core and a fiberglass-reinforced polyester laminate as the composite skin. Natural fibers are stitched into polyurethane foam to strengthen it. Experimental methods are used to evaluate the shear strength of sandwich panels with various types of natural fibers. Shear tests were carried out in accordance with ASTM C 273-61 standards, to determine the shear strength between polyurethane and composite skin.  The results show that stitching the composite core with natural fibers significantly increases the shear strength compared to unstitched panels. Varying types of natural fibers affect the mechanical performance of panels differently. The use of natural fibers improves the mechanical performance of the panels. This research shows the potential of using natural fibers as an alternative reinforcement with promising experimental results.