Alternative Integration Approaches in the Weight Function ‎Method for Crack Problems

Document Type : Research Paper

Authors

Department of Wind Energy, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde, Denmark‎

Abstract

This study proposes two alternative approaches to complement existing integration strategies used in the weight function method for linear elastic crack problems. The first approach is based on an interpolation type integration scheme and the second approach is based on Gauss quadrature. The proposed approaches enable a computationally efficient numerical integration for computing stress intensity factors in 2D fracture problems. The efficiency is gained through a comparatively low number of integration points facilitated by higher-order approximation. The integration weights only need to be computed once for a given crack length-to-width ratio and can be applied to arbitrary continuous and smooth stress distributions. The proposed approaches show excellent accuracy. In particular, the Gauss quadrature approach exhibits several orders of magnitude more accuracy compared to the most commonly used trapezoidal integration.

Keywords

Main Subjects

[1] Wu, X.R., A review and verification of analytical weight function methods in fracture mechanics, Fatigue & Fracture of Engineering Materials & Structures, 42, 2019, 2017-2042.
[2] Anderson, T. L., Fracture Mechanics – Fundamentals and Applications, Fourth Edition, Taylor & Francis Inc, London, United Kingdom, 2017.
[3] Wu, X.R., Carlsson A.J., Weight functions and stress intensity factor solutions, First Edition, Pergamon Press, Oxford, United Kingdom, 1991.
[4] Bao, R., Zhang, X., Yahaya N.A., Evaluating stress intensity factors due to weld residual stresses by the weight function and finite element methods, Engineering Fracture Mechanics, 77, 2010, 2250-2566.
[5] Moftakhar, A.A., Glinka, G., Calculation of Stress Intensity Factors by Efficient Integration of Weight Functions, Engineering Fracture Mechanics, 43(5), 1992, 749-756.
[6] Anderson, T.L., Glinka, G., A closed-form method for integrating weight functions for part-through cracks subject to Mode I loading, Engineering Fracture Mechanics, 73, 2006, 2153-2165.
[7] Corteel S., Kim J., Stanton D., Moments of orthogonal polynomials and combinatorics, In: Beveridge A., Griggs J., Hogben L., Musiker G., Tetali P. (eds), Recent Trends in Combinatorics. The IMA Volumes in Mathematics and its Applications, vol 159, Springer, Cham, 2016.
[8] Fukuda, H., Katuya, M., Alt, E.O., Matveenko, A.V., Gaussian quadrature rule for arbitrary weight function and interval, Computer Physics Communications, 167, 2005, 143-150.
[9] Maple User Manual. Toronto: Maplesoft, a division of Waterloo Maple Inc., 2019.
[10] MATLAB, version 7.10.0 (R2010a), Natick, Massachusetts: The MathWorks Inc., 2018.