FEM SIMULATION ON IMPACT DAMAGE OF CROSS-PLY LAMINATED BEAM

Finite element method (FEM)simulation on damage evolution of cross ply laminated beam specimen subjected to transverse impact is presented.The actual lamination construction and real specimen configuration were considered in dividing the finite element mesh pattern.Stress distribution in each layer was calculated.Damage initiation,mode and location of the first damage event were predicted by using failure theories.The results show that the interlaminar shear delamination failure is the dominant damage mode and it is apt to couple with the matrix cracking in 90°layers.The loading point and supporting points are the most dangerous locations in the earlier damage stage.The well-known principle of degradation of elastic properties of damaged material was used to simulate damage evolution.The stable and unstable extension of the damage zone estimated in the paper may qualitatively explain the multiple fracture in impact tests.The decrease of bending stiffness of the specimen with damage growth was also calculated and compared favourably with the experimental data.