Research On Low Velocity Impact Performance Of Fiber Metal Laminates

In recent years,fiber reinforced polymer(FRP)has been widely studied because of its characteristics of light weight,high strength and fatigue resistance.But it also has the disadvantage of poor impact resistance and low residual strength.To solve this problem,fiber metal laminate(FML)is formed by combining FRP with metal.In this paper,carbon fiber reinforced polymer(CFRP)and 304 stainless steel were combined to form carbon fiber reinforced steel laminates.The low velocity impact performance of carbon fiber reinforced steel laminates was studied through experiments and finite element simulation.The main research contents are as follows:Firstly,the theoretical mechanical properties of FML were described in detail,including the constitutive model of each material component,damage criterion and the interface bonding.It provides a theoretical basis for subsequent finite element analysis.Secondly,the static mechanical properties of CFRP and 304 stainless steel were tested.Drop weight impact test was carried out on seven groups of carbon fiber reinforced steel laminates and one group of CFRP plates.The impact energy,thickness and position of the steel plates were considered in the test.The impact test results show that the impact process can be divided into three stages: bending deformation,local invasion,breakdown or rebound.Based on the damage situation,impact load-time curve,impact load-displacement curve and absorption energy-time curve obtained from impact test,the impact process and dynamic response of carbon fiber reinforced steel laminates under different impact energy,thickness and position of steel plates were studied.The effects of the above parameters on the peak impact load,peak displacement and absorbed energy of carbon fiber reinforced steel laminates under low speed impact were investigated.Finally,the finite element model was established based on the static mechanical properties,the drop weight test results and theoretical mechanical properties of FML.The model was used to simulate the impact process and damage of carbon fiber reinforced steel laminates under low speed impact.The effects of stacking mode and hammer diameter on the impact performance of carbon fiber reinforced steel laminates under low speed impact were discussed.In summary,this paper systematically studied the damage behavior and dynamic response of carbon fiber reinforced steel laminates under low velocity impact through experiments and simulations,providing a basis for the subsequent design and application of carbon fiber reinforced steel laminates.