Simulation Of Low Velocity Impact Damage On Composite Laminates

The low velocity impact to composite material panels which is sensitive and threatening to structurestrength, and is a kind of phenomenon existing extensively in project reality. By the method of casestudy, systematic work had been done to study with the combination of composite material failurecriteria and dynamic FEM analysis bonded with FEM analysis software.(1)In this paper, FEM3D analysis for modeling and predicting the damage in carbon-epoxy laminatesubjected to low velocity impact were performed.The occurrence of matrix failure, fiber failure andthe delaminated areas were predicted by utilizing the failure criteria based on empirical relation andother developed criteria with a mean of degradation factors for materials. Failure procedures anddevelopment were stimulated by cohesive model mixed with conventional stress failure criteria.(2)The failure procedure of laminate suffered from different impact energy was modeled. withincreasingly impact energy, energy absorbing would be reflected by damage forms without anydeformation waged by elastic vibration. The ever-lasting damage area attributed to saving energy bydamage and delamination.(3)Expand of on-edge and near-edge impact was done, of which the stimulation consequencesrevealed that damage area of edge impact was larger, delamination figure of on-edge impact was half-oval, while the near-edge impact was similar to normal impact that has a relation with fiber angles.(4)Composite stiffened panels suffered by on-edge impact with a test was stimulated. Comparisonswith test data for damaged stiffened panels were provided for model verifications. A good agreementbetween analysis and experimental results for the modeland orientation of delamination were obtained.