Test methods for measuring pure mode III delamination toughness of composite

Abstract

International audienceThis paper focuses on the characterization of pure mode III delamination behavior of composite materials. The development for pure mode III delamination testing methods is reviewed. Two testing methods for mode III experiments were evaluated: a novel test proposed in our previous study, termed Edge Ring Crack Torsion (ERCT) test, and the widely used Edge Crack Torsion (ECT) test. The two methods were compared by experiment and finite element analysis. The results demonstrate the advantage of ERCT. The limitations of the ECT test are discussed. (C) 2016 Elsevier Ltd. All rights reserved

ModeIIIfracture of composite laminates with elastic couplings in edge ring crack torsion test

“…The basic material parameters of the laminates are: E 1 = E 2 = 44,250 MPa, G 12 = 4062 MPa, G 13 = G 23 = 5400 MPa, ν 12 = 0.044. 55…”

“…The ERCT configuration is shown in Figure 4A. 55 The laminate includes a PTFE layer and two identical sublaminates. A circular film with a diameter of d = 15 mm is cut off from the middle of PTFE film and placed as an insert layer between the upper and lower sub laminates to form the initial crack.…”

“…The specific stacking sequences of the laminates with the BT coupling and the BE coupling are shown in Table 1. The basic material parameters of the laminates are: E 1 = E 2 = 44,250 MPa, G 12 = 4062 MPa, G 13 = G 23 = 5400 MPa, ν 12 = 0.044 55 …”

“…A finite element model is established in Abaqus software for the laminates used in the ERCT configuration. The ERCT configuration is shown in Figure 4A 55 . The laminate includes a PTFE layer and two identical sub‐laminates.…”

“…In addition to the above test setups, researchers have recently developed some new test methods to investigate the mode III fracture of laminates. Ge et al 55 investigated mode III delamination using an edge ring crack torsion (ERCT) test on CFRP laminates through experiments and simulations. It was found that the fracture was pure mode III without the presence of mode I or mode II components.…”