| In recent years, the wide use of CFRP(Carbon-Fiber Reinforced Plastic) composite material has led to increased interest in composite repair technology. The performance assessment of repaired structures has become an important issue in study of composite repair technology. The restoration of loading capacity after repairing can be predicted by performance assessment, as well as some valuable advices can be provided for practical repairing, which will significantly reduce the repair cost and time. Thus, the research of composite bonded repaired is important in both academic and engineering applications.In this work, static strength and stability of bonded patch repaired laminates were studied with three dimensional nonlinear simulation based on ABAQUS. The main contents are as follow:Firstly, according to the failure mechanism of adhesive and composite material, a progressive damage model based on continuum damage mechanism and cohesive zone model was developed for bonded patch repaired laminates, which allowed simulation of damage initiation and propagation for repaired structures.Secondly, the strength of bonded patch repaired laminates under tension load were studied with the developed model. Loading capacity and failure process of repaired structures were analysed, which obtained the ultimate strength and failure modes. Numerical results agreed well with experiment dada. At the same time, influence of repair parameters on structures′ tension behaviour were also discussed.Finally, the stability of bonded patch repaired laminates under compression load were studied with the developed model. The buckling and post-buckling performance of repaired structures were analysed, especially in loading capacity and failure characteristics. The influence of repair parameters on structures′ loading capacity after buckling were also discussed by a series numerical calculations.Conclusions obtained in this thesis can provide some references for the bonding patch repair design of composite laminates. |
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