Ply-Cracking Damage Theory for Cross-Ply Laminate and Its Application to Finite Element Method.

Damage Behavior and Life Prediction in CFRP Cross-Ply Laminates under Fatigue Loading

“…The ply-crack density means a number of ply-through cracks per 1cm length perpendicular to the fiber direction in each ply, and for 30˚ tensile tests it is converted from a number of cracks observed on the specimen edges. Features on the stress-strain relations and ply-cracking damage are almost the same as the results already reported in the references [10,11]. Under on-axis tension, the stress-strain relations are linear up to a knee-point corresponding to the initiation of ply-cracking in 90˚ plies, and then slightly nonlinear with evolution of the ply-cracking damage and delamination.…”

“…Although the stress for ply-cracking initiation in each direction can be roughly predicted by the present method, the predictions are low in the 0.5-3ply, and high in the 2-12 ply and 2-18 ply as compared with the experimental results. This is attributed to that the residual stresses in cross-ply laminates created in the curing process are not considered in the present prediction, and that the present method can not take into consideration an influence of ply thickness, different from prediction based on the energy release rate criterion [10,11]. Fig.…”

“…As the transverse cracking and splitting are caused by micro-scale damage along the fiber direction such as matrix cracking and debonding between fibers and matrix, they are referred to as ply-cracking in this article. Since the inhomogeneity and damage modes at meso-scale have a much greater influence on the mechanical performance of laminated composites, many investigations have been carried out on the ply-cracking damage and delamination [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

OS09W0183 Fatigue behavior of CFRP cross-ply laminates under axial cyclic load

“…Therefore, the damage and nonlinear deformation should be considered in the mechanics and strength evaluation of the laminated composites. From this point of view, many investigations have been carried out on the interlaminar and splitting fracture toughness [1][2][3][4], the damage initiation and evolution under monotonic or cyclic loading [5][6][7][8][9][10][11][12][13], the nonlinear deformation, the damage model and the constitutive relations for the laminated composites [14][15][16][17][18].…”

“…In the previous reports [10,11,18], the progressive ply-cracking damage and nonlinear deformation of CFRP cross-ply laminates under axial and off-axis tension were investigated. From the experimental and numerical results, the following conclusions were obtained.…”