Experimental and numerical studies on low‐velocity impact damage of composite laminates toughened by nickel‐coated carbon fiber veil

The low-velocity impact response of carbon fiber composite laminates toughened by nickel-coated carbon fiber (NiCF) veil interleaves was investigated experimentally and numerically. The experimental results indicated that the impact resistance of laminates with a layer of NiCF veil of 34 g/m(2) inserted in the midplane was improved, especially in terms of increased peak impact force and residual compressive strength (by 16.15%), and reduced damage area (by 30.92%). The enhancement mechanisms were attributed to the breakage, pull-out, and crack bridging of the NiCF veil, as well as the peeling of nickel coating, which enhanced the carbon fiber/resin interfacial adhesion. A numerical model based on continuum damage mechanics and cohesive zone model was developed and its validity was verified. The simulation results confirmed that NiCF veils reduced energy absorption by enhancing the interlaminar properties of laminates, thereby reducing impact damage. Moreover, laminates with higher areal density and more layers of NiCF veils had higher impact force and smaller damage area, and thus had better impact resistance.