Session: DA-12-02 The Noel O'Dowd Memorial Symposium on Fracture: Fracture-2

Paper Number: 154451

154451 - A Comparative Study of Fracture Toughness J1c Measurement Based on Digital Image Correlation and Acoustic Emission Technique and the Astm D6068 Protocols 

Abstract: 

Fracture toughness J_IC is a crucial indicator for quantitatively characterizing the ability of materials to prevent crack propagation. Generally, J_IC is measured by following ASTM D6068 protocol, while this method requires duplicate multiple-specimen tests, which is complicated and wasteful of materials. Our previous study demonstrates a possibility of determining the fracture toughness J_IC by combination of digital image correlation (DIC) and acoustic emission (AE) technique. In this method, DIC technique is used to obtain the displacement and strain field on specimen surface to calculate J-integral by numerical discretization according to the rigorous definition proposed by Rice, and AE technique is used to detect the damage evolution inside the material and capture the moment of crack initiation synchronously. However, the compatibility between the proposed method and the ASTM D6068 protocol haven’t been tested yet. In this study, a set of identical three-point bending specimens were loaded to various displacements at a 2mm/min cross-head speed using a universal tensile machine, and the fracture toughness J_IC was measured both by ASTM protocol and a combination of DIC and AE technique. In addition, numerical simulation by ABAQUS was conducted to verify the testing results. Research results show that J_IC obtained by ASTM protocols, the proposed DIC and AE technique, numerical simulation are 19.01 kJ/m², 19.36 kJ/m², and 19.77 kJ/m², respectively. The good consistency in the fracture toughness proves the validity, accuracy and simplicity of the proposed method, and provide a reference for the fracture toughness measurement for other engineering materials.

Presenting Author: Yue Zhang Shijiazhuang Tiedao University

Presenting Author Biography: Yue Zhang, Lecturer, Department of Engineering Mechanics in Shijiazhuang Tiedao University, graduated from Zhejiang University, engaged in damage and failure analysis of polyethylene piping materials.

Authors:

Yue Zhang Shijiazhuang Tiedao University
Sixiang Liang Shijiazhuang Tiedao University
Zechao Liu Shijiazhuang Tiedao University