Open Access

ARTICLE

A Node-Based Smoothed eXtended Finite Element Method (NS-XFEM) for Fracture Analysis

by N. Vu-Bac¹, H. Nguyen-Xuan², L. Chen³, S. Bordas⁴, P. Kerfriden⁴, G.R. Liu⁵, T. Rabczuk¹

1 Institute of Structural Mechanics, Bauhaus-University Weimar, Marienstr. 15, D-99423 Weimar, Germany
2 Division of Computational Mechanics, Ton Duc Thang University, Ho Chi Minh City, Vietnam
3 Center for Advanced Computations in Engineering Science (ACES), Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576
4 School of Engineering, Institute of Theoretical, Applied and Computational Mechanics, Cardiff University, Wales, UK
5 Aerospace Systems Ohio Eminent Scholar University of Cincinnati, Cincinnati, OH 45221-0070

Computer Modeling in Engineering & Sciences 2011, 73(4), 331-356. https://doi.org/10.3970/cmes.2011.073.331

Abstract

This paper aims to incorporate the node-based smoothed finite element method (NS-FEM) into the extended finite element method (XFEM) to form a novel numerical method (NS-XFEM) for analyzing fracture problems of 2D elasticity. NS-FEM uses the strain smoothing technique over the smoothing domains associated with nodes to compute the system stiffness matrix, which leads to the line integrations using directly the shape function values along the boundaries of the smoothing domains. As a result, we avoid integration of the stress singularity at the crack tip. It is not necessary to divide elements cut by cracks when we replace interior integration by boundary integration, simplifying integration of the discontinuous approximation. The key advantage of the NS-XFEM is that it provides more accurate solutions compared to the XFEM-T3 element. We will show for two numerical examples that the NS-XFEM significantly improves the results in the energy norm and the stress intensity factors. For the examples studied, we obtain super-convergent results.

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Keywords

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