Single Edge Notch Tension Test on Cross-Ply Laminated Composites for Intralaminar Fracture Properties

Abstract

A systematic yet simple way to measure the fracture toughness value for a Mode I crack that occurs perpendicular to the fiber direction in a unidirectional composite is presented. Cross-ply single edge notch tension (SENT) tests combined with finite element analysis areutilized to obtain the in-plane fracture toughness value under tension in the direction of fibers. The notch length of the SENT specimen is used as a parameter to back out the fracture toughness value in a consistent manner.

Progressive Damage and Failure Prediction of Open Hole Tension and Open Hole Compression Specimens

“…5 One of the critical factors in modeling the progressive failure using a crack band approach is estimating the correct fracture toughness values as they control the post peak softening behavior and hence the failure evolution. Fiber direction fracture toughness of the 0 layer can be obtained using a single edge notch tension (SENT) test/simulation, of the [90/0]s specimen as reported in Boyd et al 10 This value is then scaled for different layups as discussed in the following section, using the approach suggested by. 4 For compressive loading, fiber direction overstress fracture toughness is not known and it is assumed to be about 25% of the value in tension.…”