Open Access

ARTICLE

The Failure Analysis of Carbon Fiber-Reinforced Epoxy Composites against Impact Loading with Numerical and Experimental Investigations

Md Salah Uddin^*
Department of Mechanical Engineering, University of Texas Permian Basin, Midland, TX 79707, USA
* Corresponding Author: Md Salah Uddin. Email:
(This article belongs to the Special Issue: Damage and Fracture of Polymer Composites)

Journal of Polymer Materials https://doi.org/10.32604/jpm.2025.070688

Received 21 July 2025; Accepted 12 November 2025; Published online 27 November 2025

Abstract

Carbon fiber-reinforced composites (CFRCs) have a wide range of applications in the aerospace, automotive, and energy sectors. A higher specific strength-to-weight ratio is desired in high-performance applications. The failure mechanism of CFRCs involves multiscale phenomena, such as failure that can occur at the matrix, fibers, interface, layers, lamina, and laminates. When an impactor hits the CFRCs, the design involves analyzing each of these stages to prevent failure and optimize the properties of CFRCs under various loading conditions. A numerical model was employed to predict the fracture toughness of CFRCs with varying weight fractions and orientations. Finite Element Analysis (FEA) was conducted at the fiber level on a micrometer scale for the CFRCs against an impact loading. Epoxy composite samples at the coupon level were prepared using the hand layup technique with carbon fibers laid at three different angles, i.e., longitudinal, transverse, and angular orientations. Samples with five different weight percentages of carbon fibers were prepared and investigated. An Izod impact tester was used to fracture the samples and characterize the energy absorption. The fractured surfaces were observed with a scanning electron microscope (SEM). The numerical and experimental results show that crack propagation is inhibited at higher loading fractions at an angular orientation by creating obstacles for the crack to propagate and arresting the dislocation motion. The fractography analysis through a scanning electron microscope exhibits how the angular orientations of the fibers are reoriented after fracture to prevent further crack propagation.

---

Keywords

Impact loading; failure analysis; carbon fiber epoxy composites; crack inhibition; fractography; and orientations

---