The Effects Of Low-Energy Impact On The Mechanical Properties Of Carbon Fiber Reinforced Polymer Laminates With Voids

This paper investigates the void morphology, the effects of porosity on mechanical properties of the CFRP laminates, the effects of the low-energy impact on the damage of CFRP laminates, discusseing the changes of the mechanical properties of CFRP laminates after the impact of low energy, simulating the CFRP laminates with voids after low-energy impact by finite element.Results show that with the increase of porosity, the voids' average length, width, ratio of length and width and area become larger as well. The voids of composite with small porosity are mainly distributed in the resin and fiber bundles, and separated to each other, voids are mainly spherical and oval with the smaller ratio of the length and the width. The voids of composite with larger porosity are mainly distributed in the interface layer, fiber bundles and resin enrichment areas, which has relatively close distance to each other, some of then even connected., there are spherical, ellipsoid of the larger ratio of the length and the width, elongated type of voids and flat disc-shaped voids. With the increase of porosity, the mechanical properties of laminates declined.With the increases of impact energy, the damage of laminates become more and more serious and the mechanical properties of laminates are getting worse, When laminates subject to the same impact energy, the larger the porosity is, the more serious damage is and the worse the properties it have.Simulating the process of the composite laminates by the impact with finite element, obtained the Von Mises stress distribution of each layer of laminates, we found that the damage of composite laminates have connection with the sequences of layers. The properties of simulated effect of the voids on laminates with the impact, which appears serious stress concentration near the voids.