Perforation resistance of CFRP beams to quasi-static and ballistic loading: The role of matrix strength


Type
Article
Change log
Authors
Yu, B 
Karthikeyan, K 
Deshpande, VS 
Fleck, NA 
Abstract

© 2017 The effect of matrix shear strength on the ballistic response of simply-supported carbon fibre reinforced plastic (CFRP) beams was explored for a flat-ended projectile. To gain insight into the deformation and failure mechanisms, the following additional tests were performed on CFRP beams: (i) quasi-static indentation tests with rigid back support and, (ii) quasi-static cropping tests. In all 3 types of tests, CFRP [0°/90°] cross-ply laminates were tested in six states of cure, such that the matrix shear strength ranges from 0.1 MPa to 100 MPa. In the quasi-static cropping tests, the composite beams failed by shear plugging (involving transverse matrix cracks, ply delamination, and fibre fracture). In contrast, indirect tension (by ply tensile failure in the fibre direction) occurred in the back-supported quasi-static indentation tests. In the ballistic tests, the CFRP beams of high matrix shear strength (30 MPa–100 MPa) failed by a shear plugging mode. When the matrix shear strength was less than 30 MPa, the failure mode and the penetration velocity doubled and occurred by indirect tension. The optimal shear strength to give adequate static and ballistic strength is on the order of 20 MPa.

Description
Keywords
Ballistics, Fibre composites, Perforation mechanisms, Shear plugging, Indirect tension
Journal Title
International Journal of Impact Engineering
Conference Name
Journal ISSN
0734-743X
1879-3509
Volume Title
108
Publisher
Elsevier
Sponsorship
European Commission Horizon 2020 (H2020) ERC (206409)
The research work was sponsored by the Office of Naval Research (ONR), U.S. (Prime Award No. N62909-14-1-N232). The raw composite materials and the autoclave manufacturing process were generously provided by Hexcel Ltd. Finally, the doctoral study of B. Yu was sponsored by the Croucher Foundation and the Cambridge Commonwealth, European & International Trust.