Title: Evaluation of mode 1 stress intensity factor for edge crack using displacement extrapolation method

Authors: L.J. Kirthan; Ramakrishna Hegde; V.A. Girisha; R. Girish Kumar

Addresses: Department of Mechanical Engineering, RV College of Engineering, Bangalore 560059, Karnataka, India ' Department of Mechanical Engineering, RV College of Engineering, Bangalore 560059, Karnataka, India ' Department of Mechanical Engineering, RV College of Engineering, Bangalore 560059, Karnataka, India ' Department of Mechanical Engineering, RV College of Engineering, Bangalore 560059, Karnataka, India

Abstract: Fracture is a failure mode due to unstable propagation of a crack due to applied stress. This paper aims towards evaluating stress intensity factor for mode 1 crack propagation using compact tension specimen using displacement extrapolation method and comparing it with analytical solutions. Compact tension specimen was tested for mode 1 crack propagation and stress intensity factor was evaluated for different crack lengths. Displacement extrapolation method was used to find the stress intensity factor by considering the displacements at the flagged nodes near the crack tip and then was compared with the analytical results. Displacement extrapolation method showed good agreement with the analytical results. The results show that the SIF increased at a very slow rate in the beginning of the crack growth and increased rapidly later. This was because of the plastic zone at the crack tip getting increased. This increased the resistance offered by the crack to the propagation.

Keywords: stress intensity factor; SINGULAR element; displacement extrapolation; edge cracks; fracture; crack propagation; crack growth; plastic zone; crack tip.

DOI: 10.1504/IJMSI.2016.079651

International Journal of Materials and Structural Integrity, 2016 Vol.10 No.1/2/3, pp.11 - 22

Received: 20 Feb 2016
Accepted: 06 Aug 2016
Published online: 06 Oct 2016 *

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