Cryogenic Tensile Properties of Carbon Fiber-Reinforced Plastic Sandwich Foam Core

Abstract

The use of carbon fiber-reinforced plastic (CFRP) foam core sandwich structures in the cryogenic tanks of launch vehicles is expected to aid in weight reduction. The tensile properties of CFRP foam core sandwich composites were investigated under cryogenic conditions. Typically, the coefficient of thermal expansion (CTE) of foam materials is much larger than that of CFRP. Under cryogenic conditions, this results in the generation of significant tensile thermal strain in the foam core, in addition to tensile mechanical strain. To identify composites with improved cryogenic behavior, the CTEs and cryogenic tensile fracture strains of several foam materials were recorded. CFRP sandwich tensile specimens with polyisocyanurate foam were tested in liquid nitrogen and assessed via finite element method analysis. The test results revealed that the polyisocyanurate foam is a potential core material for CFRP sandwich composites used in cryogenic tanks.