Numerical analysis of high velocity, oblique impacts and residual tensile strength of carbon/epoxy laminates

Kristnama, Ashwin R.; Xu, Xiaodong; Wisnom, Michael R.; Hallett, Stephen R.

Abstract

This paper presents prediction of the high velocity, oblique impact response and quasi-static residual tensile strength of thin [45/90/−45/0]2s carbon/epoxy laminates using finite element (FE) models. A High-Fidelity Finite Element Method (Hi-FEM) with an automated unit cell meshing technique was employed. The predicted impact damage, characterised by the extent of fibre failure and delamination area, was validated against results from gas-gun tests for a range of impact velocities. The numerical results captured the trend of increasing impact damage with impact energy as observed from the tests. Changes in projectile orientation before impact were shown to increase the extent of fibre failure at high impact energies, up by 38% in edge impact cases. The residual tensile strength of the impacted laminates was then investigated, where the numerical results for edge-impacted laminates agreed with the test data within 8%. On the other hand, the residual strength modelling results of centre-impacted laminates were found to be unconservative, mainly due to the extent of fibre failure predicted during impact. Machined notches were also studied for their residual tensile strength in comparison to impact induced damage. The predicted strength of edge-notched laminates was found to be in close agreement with the experimental results for edge-impacted laminates, differing by an average of 9%.

• Journal Article Type: Article
• Acceptance Date: Dec 14, 2020
• Online Publication Date: Dec 30, 2020
• Publication Date: Mar 1, 2021
• Deposit Date: Feb 15, 2021
• Publicly Available Date: Dec 31, 2021
• Journal: Composite Structures
• Print ISSN: 0263-8223
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 259
• Article Number: 113476
• DOI: https://doi.org/10.1016/j.compstruct.2020.113476
• Keywords: Civil and Structural Engineering; Ceramics and Composites
• Public URL: https://uwe-repository.worktribe.com/output/7094413
• Additional Information: This article is maintained by: Elsevier; Article Title: Numerical analysis of high velocity, oblique impacts and residual tensile strength of carbon/epoxy laminates; Journal Title: Composite Structures; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.compstruct.2020.113476; Content Type: article; Copyright: Crown Copyright © 2020 Published by Elsevier Ltd. All rights reserved.