| Because of its anisotropy,high tensile strength,high modulus,low density,high temperature resistance,corrosion resistance and good impact resistance,carbon fiber composites are widely used in the main structural components of aerospace,automotive and marine fields,etc.In the process of aircraft take-off and car driving,they will inevitably be impacted by foreign objects,so it is important to study the mechanical Therefore,it is important to study the mechanical behavior of carbon fiber composites under different forms of loading.In this paper,the mechanical properties of carbon fiber composite materials under different forms of loads are studied by combining experimental research,theoretical analysis and numerical simulation,and the research results obtained can provide theoretical basis and technical support for the application of carbon fiber composite laminates,as shown below:Firstly,the bending mechanical behavior characteristics of carbon fiber composite unidirectional plate under different span distances were experimentally investigated.The load-displacement relationship was obtained through the experimental study,and the ability of carbon fiber composite materials to resist the instability expansion of crack initiation at different span distances was clarified.The bending damage patterns of carbon fiber composite unidirectional plates at different span distances were investigated by applying digital image correlation techniques to the experimental study.Secondly,the mechanical behavior of carbon fiber composite unidirectional plates under different loading strain rates was investigated experimentally using an electronic universal testing machine and a detached Hopkinson compression bar test device.The analysis of the obtained stress-strain curves shows that the carbon fiber composite unidirectional plate has obvious strain rate effect,and the variability of the compressive strength of the carbon fiber composite unidirectional plate in the main direction is also explored.The damage mode and failure mechanism of the carbon fiber composite material are clarified by combining the ultra-high speed camera and digital image correlation techniques.Finally,experimental studies on the intrusion resistance of carbon fiber composite laminates and fiber-metal laminates with lay-up sequences of[0°/45°/90°/-45°]S and[0°/45°/90°/-45°]S2 were carried out using a one-stage light air cannon device.Based on the impact velocity and residual velocity of steel balls obtained in the experimental study,the influence of the intrusion velocity on the energy absorption of the laminate was investigated in conjunction with the law of energy conservation.Based on the experimental study,numerical simulations were carried out to determine the damage pattern of the laminate and to reveal the damage failure mechanism of the laminate during the high-speed impact. |
