Research On The Impact Behaviors Of Composite Laminate Fragment Under Different Projectile And Target Conditions

Considering its high specific strength,high specific stiffness,corrosion resistance and other property advantages,composite material have been widely used in aerospace,transportation,intelligent manufacturing and many other science and tehnology fields.Especially in the research background of aircraft,aeroengine and other structures with increasing requirements for material properties,the proportion of composite material has become an important index to evaluate the advanced level of aviation structural design.When this kind of composite structure fails due to external impact,fatigue damage and other reasons in the service process,the structural fragment will impact the surrounding structure at high speed,resulting in secondary damage,such as Aeroengine Casing Containment problem.Therefore,it is important to research the damage failure mechanism and dynamic mechanical response of composite structure fragment as impact body.In this paper,based on the design and construction of laminated projectile impact test system,through the ballistic impact test of composite fragment projectile combined with the finite element numerical simulation research,the impact failure behavior of carbon fiber reinforced epoxy composite laminate fragment projectile under different projectile target conditions and related influencing factors were analyzed.Firstly,in order to carry out experimental research of dynamic impact behavior of composite fragments on the surrounding structure,the composite laminate projectile impact experiment system had been designed and estabilished based on light gas gun device,which was composed of light gas gun loading system,target cabin clamping protection system and dynamic response measurement system.The 3D-DIC technology had been successfully used in this composite laminate projectile impact experiment system.Some mechanical properties of the used composites were obtained by quasistatic tensile and compression experiments of unidirectional composite laminates.Secondly,based on the impact experiment system established in this paper,the ballistic impact tests of composite fragments as carbon fiber reinforced resin matrix composite laminates impacting steel plate and aluminum alloy sheet under different impact velocities are carried out,and the failure process,damage mode,kinetic energy dissipation and dynamical mechanical response of target plate were analyzed,the effects of impact velocity and laminate stacking method on the impact response were compared.Finally,based on the experimental analysis,the macro-scale ballistic impact finite element model of fiber reinforced composite laminate fragments was established,which was based on the three-dimensional progressive damage model of composite projectile and ductile damage model of alluminum alloy target,considering the different damage modes,strain rate effects and interface properties of composite laminates,the impact process and dynamic response of composite laminate fragments on aluminum alloy target was simulated and analyzed.By comparing with the experimental results,the validity of this simulation model was verified.And based on simulation methods,the influence of target curvature on the impact damage behavior of carbon fiber resin matrix composite laminates fragment at different speeds were researched and discussed。...