Integral forming of continuous CFRP sandwich sheet by additive manufacturing

Abstract

Sandwich sheets comprising continuous carbon fiber reinforced plastics (CFRP) are applied mainly in the aerospace industry due to their light weight and high rigidity. However, sandwich sheets require separate formation and bonding of the face sheets and core, resulting in high labor costs and early fracture due to delamination of the adhesive layer. The purpose of this study is to overcome these problems by integrating sandwich sheet using additive manufacturing. The mechanical properties of the integrally formed sandwich sheets were compared with those of adhesively formed sandwich sheets using a three-point bending test. The strain distribution was captured by digital image correlation (DIC) during the test. Additionally, the geometric design parameters of a core with superior mechanical properties were investigated. The test results showed that the integrally formed specimens exhibited superior properties compared to those of the adhesively formed specimens. It was also observed that the larger the width angle of the corrugated core, the better the mechanical properties.