Research On Mechanical Repair Of Composite Laminates

Composite materials inevitably suffer various damages during use,leading to a decrease in structural performance.Mechanical repairs introduce new stress concentrations and lower repair efficiencies than glued repairs,but they are easy to operate,reliable and disassembled,making them ideal for use as a temporary repair method and as a permanent repair method for structures which need high reliability and carry heavy load.In this paper,research was carried out on mechanical repair of composite Laminates containing high-speed penetration impact damage,using open-hole equivalent method.The main content of this thesis is stated as follows:(1)The test about mechanical repair of open-hole laminates was carried out,by comparing the damage load,failure mode and strain distribution at damage,to study on the impact of open-hole damage on the laminate and the repair effect of mechanical repair.At the same time,three-dimensional finite element model combined with progressive damage analysis method and cohesive zone model were used to simulate the test piece to verify the validity of the analysis method.(2)The numerical analysis method was used to analyze the repair parameters of the bolted repair structure of open-hole composite laminates,and the contrastive study of the influence law and influence degree of each repair parameter on the structure performance was carried out.(3)The numerical analysis method was used to analyze the repair parameters of the hybrid repair structure of open-hole composite laminates,and the contrastive study of the influence law and influence degree of each repair parameter on the structure performance was carried out.