Numerical Simulation Of Composite Laminated Plates Subjected To Impact

Fiber reinforced composites has abroad application in many fields,which are the aerospace industry,transportation,architecture,owing to its many advantage properties,such as light weight,higher specific stiffness and.specific intensity,excellent anti-flexibility and so on.Composites subjected to low-speed impact often occur fiber breakage,matrix cracking,inter-ply delaminations and so on,which has important pratical significance to do research on energy absorption of composites under damage under low-speed impact.This paper studies dynamic impact damages and energy absorption of laminated plates under high-velocity and low-velocity impact,which contributes to the contents as follows:1.The stress-strain relationship of single layer composite plates is deduced by orthotropy elasticity theory.The article analyzes the failure criterion of fiber reinforced composites,rules of material degradation and their applicability.2.Directional 163 shell element which is selected to simulate laminated plates,and bonding layer is ignored.Besides,suitable material model and CHANG-CHANG failure rule are applied to model composite laminates subjected to high-velocity impact of bullet.The reliability of numerical method is verified compared with the experimental results.3.The change of bullet’s velocity,acceleration,energy,and composite laminates’ stress are analyzed under high-speed impact.Meanwhile energy absorption of composites laminates increases with higher velocity of impact;specific energy absorption of that changes with target’s surface density affected by ply thickness;the target’s energy absorption is decreasing with the increase of layer angle.4.Dynamic response of composite laminates in low-velocity impact is researched by numerical simulation,in which SOLID164 and special SOLID ELEMENT 19 are applied to simulate sublaminate and adhesive layer respectively,and modified CHANG-CHANG damage criterion,bilinear damage criterion are applied as sublayer’ and bonding layer’ damage criterion.The validity of numerical method is verified by comparing with experimental results.5.The contact impact force of laminated plates,the damage evolution of cohesive layer and sublayers with different angles are discussed by numerical simulation.The results show that the maximum contact force,the damage area of adhesive layer,and the displacement of the center of laminated plates is increasing with the increase of impact energy and it shows that the impact energy is not directly relative to impact duration and energy absorption of composites laminates.Meanwhile the results of different geometry shapes of impactor such as hemispherical flat and conical show that the damage area of adhesive layer and the displacement of the center of laminated plates is biggest under conical impactor,and that is smallest under flat impactor.