Evaluation of the mechanical properties and deformability of metal-based composite sheets made of thin stainless-steel sheets and carbon fiber reinforced plastics

Ultra-lightweight sheets with excellent deformability are required for the development of new air vehicles, as well as greener conventional vehicles. Carbon fiber reinforced plastic (CFRP) has a high specific rigidity and strength but is too expensive to be used in general machine parts. Using CFRP enhances the properties of the material itself. Furthermore, developing the usage of the material also makes the mechanical properties higher. The purpose of this paper is to combine both methods and produce a material with better rigidity and deformability. The new structure was proposed considering the moment of inertia of area. This structure was excellent not only in terms of rigidity but also in the moldability of the core. In addition, the effects of the structure dimensions on the moldability, bonding strength and flexural rigidity were determined using finite element (FE) analysis and experiments. By comparing the results of the FE analysis conducted under pure bending conditions with three-point bending experiment, it was found that the FE analysis of pure bending fails to predict the three-point bending stiffness because the shear stress has a significant effect on the experimental measurements. By modifying the model from pure bending to three-point bending, the experimental results were well reproduced by the 3D FE analysis.