Investigation on the Effect of Spring-In Distortion on Strength of a Bimaterial Beam

Abstract

The relatively low fabrication precision of CFRP (carbon fiber-reinforced plastics) is an obstacle to the bimaterial specimens’ repeatability and reproducibility. A solution could be found by fabricating certain metallic specimens to fit the CFRP in order to obtain the exact experimental states of the bimaterial beam and accomplish the repeatability and reproducibility of the composite tests. The paper investigates the effect of spring-in distortion on a bimaterial beam’s ultimate tensile strength by the designed experiments. Typical assembling process of the bimaterial beam containing spring-in distortion is analyzed. Bimaterial specimens are designed to represent the typical spring-in distortion. Tension tests are carried out based on available standards to determine the CFRP’s behaviors in the numerical model. Correlation analysis between the real assembling state and the experimental assembling state is conducted in detail. Based on the verified numerical model of the experimental bimaterial beam, the numerical model of the real bimaterial beam is constructed. The effect of spring-in distortion on a bimaterial beam’s ultimate tensile strength is obtained. The reported work presents a solution of fabricating certain metallic specimens to obtain the exact states of the bimaterial beam containing spring-in distortion. It will enhance the understanding of the composite components’ assembly and help to systematically improve the composites’ assembling efficiency in the civil aircraft industry.