Evaluation of Fracture Parameters by Coupling the Edge-Based Smoothed Finite Element Method and the Scaled Boundary Finite Element Method

Document Type : Research Paper

Authors

1 CSIR-Structural Engineering Research Centre, Chennai-600113, India

2 Integrated Modelling and Simulation Lab, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, India

Abstract

This paper presents a technique to evaluate the fracture parameters by combining the edge based smoothed finite element method (ESFEM) and the scaled boundary finite element method (SBFEM). A semi-analytical solution is sought in the region close to the vicinity of the crack tip using the SBFEM, whilst, the ESFEM is used for the rest of the domain. As both methods satisfy the partition of unity and the compatibility condition, the stiffness matrices obtained from both methods can be assembled as in the conventional finite element method. The stress intensity factors (SIFs) are computed directly from their definition. Numerical examples of linear elastic bodies with cracks are solved without requiring additional post-processing techniques. The SIFs computed using the proposed technique are in a good agreement with the reference solutions. A crack propagation study is also carried out with minimal local remeshing to show the robustness of the proposed technique. The maximum circumferential stress criterion is used to predict the direction of propagation.

Keywords

Main Subjects

[1] Song, J.H., Areias, P.M.A., Belytschko, T., A method for dynamic crack and shear band propagation with phantom nodes. International Journal for Numerical Methods in Engineering, 67(6), 2006, 868–893.
[2] Hamdia, K.M., Silani, M., Zhuang, X., He, P., Rabczuk, T., Stochastic analysis of the fracture toughness of polymeric nanoparticle composites using polynomial chaos expansions. International Journal of Fracture, 206(2), 2017, 215–227.
[3] Braun, J., Sambridge, M., A numerical method for solving partial differential equations on highly irregular evolving grids. Nature, 376, 1995, 655–660.
[4] Hughes, T.J.R., Cottrell, J.A., Bazilevs, Y., Isogeometric analysis: Cad, finite elements, nurbs, exact geometry and mesh refinement. Computer Methods in Applied Mechanics and Engineering, 194(39), 2005, 4135 – 4195.
[5] Ghorashi, S.Sh., Valizadeh, N., Mohammadi, S., Rabczuk, T., T-spline based xiga for fracture analysis of orthotropic media. Computers and Structures, 147, 2015, 138 – 146, CIVIL-COMP.
[6] Valizadeh, N., Bazilevs, Y., Chen, J.S., Rabczuk, T., A coupled igameshfree discretization of arbitrary order of accuracy and without global geometry parameterization. Computer Methods in Applied Mechanics and Engineering, 293, 2015, 20 – 37.
[7] Liu, G.R., Dai, K.Y., Nguyen, T.T., A smoothed finite element method for mechanics problems. Computational Mechanics, 39(6), 2007, 859–877.
[8] Bordas, S.P.A., Rabczuk, T., Hung, N.X., Nguyen, V.P., Natarajan, S., Bog, T., Quan, D.M., Hiep, N.V., Strain smoothing in fem and xfem. Computers & structures, 88(23), 2010, 1419–1443.
[9] Surendran, M., Natarajan, S., Bordas, S.P.A., Palani, G.S., Linear smoothed extended finite element method. International Journal for Numerical Methods in Engineering, 112(12), 2017, 1733–1749.
[10] Nguyen-Thoi, T., Liu, G.R., Nguyen-Xuan, H., An n-sided polygonal edge-based smoothed finite element method (nes-fem) for solid mechanics. International Journal for Numerical Methods in Biomedical Engineering, 27(9), 2011, 1446–1472.
[11] Dai, K.Y., Liu, G.R., Nguyen, T.T., An n-sided polygonal smoothed finite element method (nsfem) for solid mechanics. Finite Elements in Analysis and Design, 43(11), 2007, 847 – 860.
[12] Francis, A., Ortiz-Bernardin, A., Bordas, S.P.A., Natarajan, S., Linear smoothed polygonal and polyhedral finite elements. International Journal for Numerical Methods in Engineering, 109(9), 2017, 1263–1288.
[13] Liu, G.R., Nguyen-Thoi, T., Lam, K.Y., An edge-based smoothed finite element method (es-fem) for static, free and forced vibration analyses of solids. Journal of Sound and Vibration, 320(4), 2009, 1100–1130.
[14] Song, C., Wolf. J.P., Consistent infinitesimal finite-element cell method: three-dimensional vector wave equation. International Journal for Numerical Methods in Engineering, 39, 1996, 2189–2208.
[15] Song, C., Wolf, J.P., The scaled boundary finite-element methodalias consistent infinitesimal finite-element cell methodfor elastodynamics. Computer Methods in Applied Mechanics and Engineering, 147(3-4), 1997, 329–355.
[16] Ooi, E.T., Natarajan, S., Song, C., Ooi, E.H., Dynamic fracture simulations using the scaled boundary finite element method on hybrid polygon-quadtree meshes. International Journal of Impact Engineering, 90, 2016, 154–164.
[17] Song, C., Tin-Loi, F., Gao, W., A definition and evaluation procedure of generalized stress intensity factors at cracks and multi-material wedges. Engineering Fracture Mechanics, 77(12), 2010, 2316–2336.
[18] Natarajan, S., Song, C., Representation of singular fields without asymptotic enrichment in the extended finite element method. International Journal for Numerical Methods in Engineering, 96(13), 2013, 813–841.
[19] Li, C., Man, H., Song, C., Gao, W., Fracture analysis of piezoelectric materials using the scaled boundary finite element method. Engineering Fracture Mechanics, 97(1), 2012, 52–71.
[20] Tat, E., Sundararajan, O., Song, C., Tin-loi, F., Crack propagation modelling in functionally graded. 2015, p.p. 87–105.
[21] Ooi, E.T., Song, C., Tin-Loi, F., A scaled boundary polygon formulation for elasto-plastic analyses. Computer Methods in Applied Mechanics and Engineering, 268, 2014, 905–937.
[22] Song, C., Wolf, J.P., Semi-analytical representation of stress singularities as occurring in cracks in anisotropic multi-materials with the scaled boundary finite-element method. Computers and Structures, 80(2), 2002, 183–197.
[23] Chen, J.S., Wu, C.T., Yoon, S., You, Y., A stabilized conforming nodal integration for galerkin mesh-free methods. International journal for numerical methods in engineering, 50(2), 2001, 435–466.
[24] Liu, G.R., Nguyen-Thoi, T., Nguyen-Xuan, H.B., Lam, K.Y., A node-based smoothed finite element method (ns-fem) for upper bound solutions to solid mechanics problems. Computers & structures, 87(1), 2009, 14–26.
[25] Deeks, A.J., Wolf, J.P., A virtual work derivation of the scaled boundary finite-element method for elastostatics. Computational Mechanics, 28(6), 2002, 489–504.
[26] Sih, G.C., Strain-energy-density factor applied to mixed mode crack problems, International Journal of Fracture, 10(3), 1974, 305–321.
[27] Rao, B.N., Rahman, S., A coupled meshless-finite element method for fracture analysis of cracks. International Journal of Pressure Vessels and Piping, 78, 2001, 647 –657.