Explosion Resistance And Failure Mechanism Of Carbon Fiber Metal Laminates

Carbon fiber composite is a new kind of material,which has many advantages,such as high stiffness,high tensile strength,light weight,chemical corrosion resistance,high temperature resistance and low thermal expansion.At present,carbon fiber has been widely used in aerospace,automobile manufacturing,national defense and other high-tech industries.Carbon fibre-metal laminate is a new kind of composite material,which is composed of metal or alloy materials and carbon fibre composites alternately laminated under specific temperature and pressure.Compared with single metal materials,carbon fiber metal laminates of the same thickness are lighter in weight and can save a lot of energy consumption when applied to aircraft and automobiles.In addition,carbon fibre composites can effectively inhibit interlaminar crack growth,and soon become a new material favored by all walks of life.In recent years,the dynamic response of fiber-reinforced metal laminates under explosive loading has gradually become a hot topic.However,there are few experimental studies on the dynamic response of lightweight materials or composite materials under explosive loading in China,and there are still many problems to be solved urgently.It is believed that with the development of science and technology and the deepening of research,fibre metal laminates will be more and more widely used in industrial engineering.In this paper,a self-made impact pendulum system is used to carry out explosive loading experiments on carbon fiber metal laminates.The deformation failure modes and failure mechanisms of carbon fiber metal laminates under explosive loading are systematically studied by means of explosive loading.Different loading impulses are obtained by changing the quality of explosives in the experiments,and different panel configurations and different impulses are analyzed.Deformation failure modes and plastic dynamic response process of carbon fibre-aluminium alloy laminates are measured.The experimental results show that most of the deformation failure modes of CFRP-aluminium alloy laminates are non-elastic large deformation,which is defined as Mode I.The damage of pure aluminium laminates without composite layer is characterized by tensile tearing,which is defined as Mode II.According to the damage characteristics of the specimens,the specimens are divided into three different deformation regions: A.clamping region B.global deformation region C.local deformation region.Under the impact of explosive load,the main deformation failure characteristics of carbon fiber metal laminates are large plastic deformation and local failure of aluminum alloy layer,matrix failure and fiber fracture of fiber composite layer,internal delamination of composite layer and stripping of metal layer and composite layer.The deformation of carbon fibre metal laminates is continuous and symmetrical.With the increase of impulse,the whole deformation area and residual deflection of the specimens increase,and the local plastic deformation increases gradually.The failure characteristics of the laminates are delamination,peeling and matrix failure.Under the same impulse loading,carbon fiber metal laminates have stronger explosion resistance than pure aluminium laminates.With the increase of carbon fiber layers,the laminates will absorb more energy and have better explosion resistance.Based on the experimental results,the finite element software ABAQUS was used to simulate the dynamic response of explosive impact carbon fiber metal laminates.The impact loading process of the structure was simulated.The velocity,displacement,deformation resistance and energy absorption capacity of carbon fiber metal laminates were analyzed and studied.Deformation failure modes of front and rear plates are obtained in the simulation,which are basically consistent with the damage and deformation of specimens after explosive impact in the experiment.For example,matrix rupture,delamination with aluminium alloy plate,shear deformation occurs in the whole deformation area,interlayer separation at the center of cross section and distortion of cell in the simulation,shear slip in the whole deformation area is large.The central velocity of the local deformed area of the panel quickly reaches its peak value after detonation.With the deformation of the laminate,the velocity begins to decrease,and the central velocity of the front and rear panels almost begins to change at the same time.The maximum deflection in the simulation is basically the same as that measured in the experiment.The maximum deflection time of the finite element model is between 0.5 ms and 1 ms.The maximum deflection of CFRP metal laminates with the same type of ply increases with the increase of the impulse.Under the same impulse,the maximum deflection of CFRP metal laminates decreases with the increase of the ply.In the process of absorbing energy,plastic deformation absorbs a large proportion of energy,while elastic strain absorbs a small part of impact energy.With the increase of impulse,the energy absorbed by plastic deformation increases,but the relative energy absorbed by elastic deformation decreases and the relative energy absorbed by elastic deformation increases.