Mechanical Properties of Laminates after Injection Repair

Abstract

The tensile and compressive mechanical properties of laminates repaired by injection repair were experimentally studied, and the influences of repair on strength, stiffness and failure mode were evaluated. Control experiments between pristine, damaged and repaired specimens were designed, which including tensile and buckling unrestrained compression. The strain gauges were used to collect the deformation data in the test, and all the experimental data were analyzed and explained. The results demonstrate that strength of half-depth damage laminates is partially restored after repair. Strength recovery rate of tensile strength is 73.7% and that of buckling is 77.4%, and the weakest area is a filling area or the interface of panel and filler. Strength and stiffness of damaged specimens are reduced due to the coupling between extension/ compression and bending load as well as stress concentration, which are caused by the missing of material in damaged area. The stiffness of filler is smaller than that of motherboard, and the filler reduces the asymmetry of the damaged laminates and increases the stiffness of the repaired laminates.

Keywords

• composite laminate
• injection repair
• failure mode
• mechanical properties