Establishment of Failure Simulation Models for Bonding of Carbon Fiber Laminated Skins and Cores in Monocoque Structures Based on Formula Student Racing Cars

In Formula SAE , the primary function of the frame is to provide structural support for the different components and withstand the applied load. Traditional truss steel tube body have drawbacks such as low strength and high weight, which has led most Formula Student teams worldwide to adopt monocoque made of carbon fiber composites, which are lighter and stronger. Enhancing the mechanical performance of carbon fiber laminates has been a key focus of research for these teams. In three point bending tests of carbon fiber laminates, the outer skin is primarily subjected to tensile forces. This results in significant stress at the adhesive layer between the skin and the core material at both ends of the laminate, leading to potential adhesive failure. Consequently, experimental boards often exhibit delamination between the outer skin and the core material, and premature core crushing, which compromises the mechanical performance of the laminate and fails to pass the Structural Equivalency Spreadsheet. To address this issue, previous solutions have involved increasing the number of carbon fiber skin layers and choosing higher-density core materials, leading to redundant laminate designs in monocoque bodies. Therefore, it is necessary to consider the influence of the bonding factor of toughened epoxy prepreg film on the mechanical properties of the laminated plate when conducting the experimental simulation of the laminated plate. This paper introduces adhesive failure factors into the simulation model, establishes a comprehensive simulation framework based on the bonding performance of GXA-120 toughened epoxy prepreg film, and validates it through actual three point bending tests, aiming to improve the accuracy of laminate experimental simulations and thereby enhance the efficiency of laminate design for the teams.