Study On Preparation And Impact Resistance Of Corrugated Sandwich Thermoplastic Carbon Fiber Metal Laminates

Fiber Metal Laminates(FMLs)is a composite material formed by laying and curing the thin metal plate and the fiber composite material.Because of its excellent mechanical properties,the laminate is widely used in aerospace,transportation and other fields.The low speed of fiber-metal laminates has been studied extensively by scholars at home and abroad and a lot of research results have been obtained.The study of fiber metal laminates started late in our country,and there is still insufficient research on fiber metal laminates.In this paper,the structure optimization and matrix strengthening of fiber-metal laminates are studied and low-speed impact experiments and finite element simulation are carried out.The main contents of this paper are as follows:In this paper,the mechanical damage models of aluminum plate,single layer composite material and interface layer are established,and the simulation results are compared with the experimental results to verify the effectiveness of the model.The simulation results show that when the fiber metal laminates are impacted,the layered damage occurs first,followed by fiber and matrix fracture damage,plastic deformation of aluminum plate and aluminum plate fracture.The crack of corrugated aluminum plate occurs at the crest of the wave,and the crack is narrower than that of the aluminum plate on the lower side.The corrugated sandwich carbon fiber metal laminates were prepared and the lowspeed impact tests were carried out on the laminates with different impact energies according to the relevant standards of low-speed impact.The impact resistance of the laminates was analyzed according to the obtained data and the visible damage of the laminates after impact.The laminates with a height difference of 0.2mm showed the best impact resistance,the lowest surface visible damage and internal damage after impact load,higher peak load and better energy absorption characteristics.Particles(PCF,SCF and CNF)with a concentration of 0.3wt% were sprayed onto the surface of the prepreg strip,which was then used to prepare carbon fiber metal laminates.The addition of 0.3wt% particles significantly enhanced the impact resistance of the carbon fiber metal laminates,resulting in lower surface visible damage,higher peak load and lower punch displacement,among which the improvement effect of CNF particles was the strongest.The addition of particles enhances the strength of the adjacent layers between the carbon fiber metal laminates and the resin,thereby reducing the interface delamination and matrix cracking,while reducing the laminate deflection,aluminum plate damage,and aluminum/composite debonding.