A Study on the Impact Characteristics of CFRP Composites by Charpy Impact Test and Residual Bending Strength Evaluation

Abstract

Carbon fiber composites are inherently vulnerable to impact due to the brittleness of the matrix and the macroscopic interface characteristics between the fiber and matrix. For composite structures such as wind turbine blades and robotic arms, which are subject to dynamic bending loads, it is critical to assess both the absorbed energy and the residual bending strength. In this study, a Charpy three-point bending impact test was conducted to investigate the damage and residual bending strength characteristics of the composite specimens. The results showed that the absorbed energy was superior in unidirectional fiber composites compared to fabric composites, and that aluminum, which has a larger plastic deformation region, exhibited higher absorbed energy values than composite materials. The minimum impact energy required for failure was approximately 10.6% higher in unidirectional fiber composites compared to fabric composites, which closely correlated with a similar increase in absorbed energy (10.2%). Additionally, the maximum load during the impact showed a trend similar to the static bending failure load and exhibited values higher than the static bending failure load.