| Because of high specific strength and high specific stiffness,composite laminates have been more and more widely used in aeronautics and astronautics industry.At the same time,the composite repair technology is attracting more attention.The performance assessment of repaired structures is very important in study of composite repair technology.The ultimate strength of repaired structures can be predicted by performance assessment and the repair parameters can be optimized based on the predicted results,which will significantly reduce the repair time and the repair cost.In this paper,tensile properties of scarf repaired composite laminates were studied with three dimensional simulation based on ABAQUS.The main contents are as follow:First,according to the failure mechanism of adhesive and composite material,the composite damage is judged by the 3D Hashin failure criteria and the adhesive damage is judged by the maximum shear stress criteria.And then a progressive damage model was developed for scarf repaired laminates based on the predetermined failure criteria and stiffness degradation strategy,which allowed simulation of damage initiation and propagation for repaired structures.Next,the ultimate strengths of scarf repaired laminates under tension load were studied in this paper.Loading capacity and failure process of repaired structures were analysed with the developed model.Numerical results agreed well with experiment data.On this basis,the differences in tensile property of unpenetrated scarf repaired laminate and the penetrated scarf repaired laminate were further studied.Finally,the variation of tensile strength with different scarf ratio and different scarf depth in scarf repaired laminates was studied with the developed model.Moreover,the influences of adhesive thickness and additional layer on tensile property of the repaired structures were discussed.Conclusions obtained in this article can provide some references for the scarf repair design of composite laminates. |
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