Table of Contents
Journal of Composites
Volume 2014, Article ID 956268, 10 pages
Research Article

Generation of R-Curve from 4ENF Specimens: An Experimental Study

1Faculty of Mechanical Engineering, Sardar Raja College of Engineering, Alangulam, Tirunelveli 627808, India
2Faculty of Mechanical Engineering, Government College of Engineering, Tirunelveli 627007, India

Received 9 July 2014; Revised 21 October 2014; Accepted 23 October 2014; Published 12 November 2014

Academic Editor: Baozhong Sun

Copyright © 2014 V. Alfred Franklin and T. Christopher. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The experimental determination of the resistance to delamination is very important in aerospace applications as composite materials have superior properties only in the fiber direction. To measure the interlaminar fracture toughness of composite materials, different kinds of specimens and experimental methods are available. This article examines the fracture energy of four-point end-notched flexure (4ENF) composite specimens made of carbon/epoxy and glass/epoxy. Experiments were conducted on these laminates and the mode II fracture energy, , was evaluated using compliance method and was compared with beam theory solution. The crack growth resistance curve (R-curve) for these specimens was generated and the found glass/epoxy shows higher toughness values than carbon/epoxy composite. From this study, it was observed that R-curve effect in 4ENF specimens is quite mild, which means that the measured delamination toughness, , is more accurate.