Improving bending characteristics of FRP sandwich structures with reinforcement webs

Abstract

Sandwich-structure materials consist of a high-strength skin material and a lightweight core material. The advantages of sandwich structures are known to include excellent mechanical properties and low weight. Sandwich structures are lightweight because of their lightweight core; meanwhile, the skin structure provides mechanical strength and bears bending stress. Carbon-fiber-reinforced plastic (CFRP) is a high-specific-strength and high-specific-rigidity material. In recent years, CFRP sandwich structures have been used in aerospace applications due to their lightweight properties. However, soft-core members such as plastic foam materials have low rigidity and therefore may not exhibit adequate function as a sandwich structure. Webs can make up for the lack of rigidity of soft core members. Consequently, sandwich structures with reinforcement webs offer higher strength than sandwich structures without reinforcement webs. This study focused on reinforcement webs suitable for use in CFRP sandwich structures by evaluating the bending characteristics of CFRP sandwich structures with reinforcement webs. Experimental results demonstrated that CFRP sandwich structures with reinforcement webs had improved bending strength. The effects of the spacing interval of reinforcement webs and the number of layers of carbon fiber fabric on the bending characteristics of CFRP sandwich structures were also examined. Finally, an optimal condition model was created for CFRP sandwich structures with reinforcement webs.