Multiphysics Analysis of CFRP Charpy Tests by varying Temperatures

Abstract

Carbon Fiber Reinforced Polymer (CFRP) composites have emerged as a major class of structural materials that have a significant potential use as a substitute for metals in aerospace, marine, automotive, and architecture due to their higher-strength-to-weight-ratio. CFRP is well suited for various applications, but their mechanical properties such as 'low-velocity impact resistance' are not well studied. In this study, the low-velocity impact resistance of CFRP woven composite was investigated with the help of Charpy impact tests. The CFRP samples were tested at room temperature (22°C) and at low temperature (-20°C). The experimental results indicated about 10% drop in energy-absorbing capability of CFRP samples at low temperatures in comparison to room temperature. The experimental results obtained for the room temperature were validated through finite element simulations using ANSYS® Workbench Explicit Dynamics. The mesh sensitivity analysis was performed to improve the accuracy of the finite element model. The numerical results helped to narrow down on the CFRP material properties that changed with temperature drop. It was found at-20°C, orthotropic Elasticity (Young's moduli in three mutually perpendicular directions) increases for CFRP woven composite as compared to room temperature (22°C), however the CFRP become brittle and there is a significant drop in their toughness. The current outcomes are useful for applications using CFRP under impact loading at low temperatures.