DOI QR코드

DOI QR Code

Strategy for refinement of nodal densities and integration cells in EFG technique

  • Patel, Bhavana S.S. (National Institute of Technology Karnataka) ;
  • Narayan, Babu K.S. (National Institute of Technology Karnataka) ;
  • Venkataramana, Katta (National Institute of Technology Karnataka)
  • Received : 2015.08.15
  • Accepted : 2016.06.28
  • Published : 2016.09.10

Abstract

MeshFree methods have become popular owing to the ease with which high stress gradients can be identified and node density distribution can be reformulated to accomplish faster convergence. This paper presents a strategy for nodal density refinement with strain energy as basis in Element-Free Galerkin MeshFree technique. Two popular flat plate problems are considered for the demonstration of the proposed strategies. Issue of integration errors introduced during nodal density refinement have been addressed by suggesting integration cell refinement. High stress effects around two symmetrical semi-circular notches under in-plane axial load have been addressed in the first problem. The second considers crack propagation under mode I and mode II fracture loading by the way of introducing high stress intensity through line crack. The computational efficacy of the adaptive refinement strategies proposed has been highlighted.

Keywords

References

  1. Amani, J., Saboor Bagherzadeh, A. and Rabczuk, T. (2014), "Error estimate and adaptive refinement in mixed discrete least squares meshless method", Math. Prob. Eng., Article ID 721240, 16
  2. Belytschko, T., Lu, Y.Y. and Gu, L. (1995), "Crack propagation by element-free Galerkin methods", Eng. Fract. Mech., 51(2), 295-315. https://doi.org/10.1016/0013-7944(94)00153-9
  3. Belytschko, T. and Black, T. (1999), "Elastic crack growth in finite elements with minimal remeshing", Int. J. Numer. Methd. Eng., 45(5), 601-620. https://doi.org/10.1002/(SICI)1097-0207(19990620)45:5<601::AID-NME598>3.0.CO;2-S
  4. Bordas, S., Rabczuk, T. and Zi, G. (2008), "Three-dimensional crack initiation, propagation, branching and junction in non-linear materials by an extended meshfree method without asymptotic enrichment", Eng. Fract. Mech., 75(5), 943-960. https://doi.org/10.1016/j.engfracmech.2007.05.010
  5. Bouchard, P.O., Bay, F. and Chastel, Y. (2003), "Numerical modelling of crack propagation: automatic remeshing and comparison of different criteria", Comp. Methd. Appl. Mech. Eng., 192(35), 3887-3908. https://doi.org/10.1016/S0045-7825(03)00391-8
  6. Chen, L., Zhang, G.Y., Zhang, J., Nguyen-Thoi, T. and Tang, Q. (2011), "An adaptive edge-based smoothed point interpolation method for mechanics problems", Int. J. Comput. Math., 88(11), 2379-2402. https://doi.org/10.1080/00207160.2010.539682
  7. Chow, W.T. and Atluri, S.N. (1995), "Finite element calculation of stress intensity factors for interfacial crack using virtual crack closure integral", Comput. Mech., 16(6), 417-425. https://doi.org/10.1007/BF00370563
  8. Dolbow, J., Moes, N. and Belytschko, T. (2000), "Discontinuous enrichment in finite elements with a partition of unity method", Finite Elem. Anal. Des., 36(3), 235-260. https://doi.org/10.1016/S0168-874X(00)00035-4
  9. Eigel, M., George, E. and Kirkilionis, M. (2010), "A mesh-free partition of unity method for diffusion equations on complex domains", IMA J. Numer. Anal., 30(3), 629-653. https://doi.org/10.1093/imanum/drn053
  10. Fleming, M., Chu, Y.A., Moran, B., Belytschko, T., Lu, Y.Y. and Gu, L. (1997), "Enriched element-free Galerkin methods for crack tip fields", Int. J. Numer. Meth. Eng., 40(8), 1483-1504 https://doi.org/10.1002/(SICI)1097-0207(19970430)40:8<1483::AID-NME123>3.0.CO;2-6
  11. Giner, E., Sukumar, N., Tarancon, J.E. and Fuenmayor, F.J. (2009), "An Abaqus implementation of the extended finite element method", Eng. Fract. Mech., 76(3), 347-368. https://doi.org/10.1016/j.engfracmech.2008.10.015
  12. Haussler-Combe, U. and Korn, C. (1998), "An adaptive approach with the element-free-Galerkin method", Comput. Meth. Appl. Mech. Eng., 162(1), 203-222. https://doi.org/10.1016/S0045-7825(97)00344-7
  13. Joldes, G.R., Wittek, A. and Miller, K. (2015), "Adaptive numerical integration in Element-Free Galerkin methods for elliptic boundary value problems", Eng. Anal. Bound. Elem., 51, 52-63. https://doi.org/10.1016/j.enganabound.2014.10.007
  14. Krysl, P. and Belytschko, T. (1999), "The Element Free Galerkin method for dynamic propagation of arbitrary 3D cracks", Int. J. Numer. Meth. Eng., 44(6), 767-800. https://doi.org/10.1002/(SICI)1097-0207(19990228)44:6<767::AID-NME524>3.0.CO;2-G
  15. Liu, G.R. and Tu, Z.H. (2002), "An adaptive procedure based on background cells for meshless methods", Comput. Meth. Appl. Mech. Eng., 191(17), 1923-1943. https://doi.org/10.1016/S0045-7825(01)00360-7
  16. Liu, G.R. (2009), Meshfree methods: moving beyond the finite element method, Taylor & Francis.
  17. Menouillard, T. and Belytschko, T. (2010), "Dynamic fracture with meshfree enriched XFEM", Aata Mechanica, 213(1-2), 53-69. https://doi.org/10.1007/s00707-009-0275-z
  18. Mergheim, J., Kuhl, E. and Steinmann, P. (2005), "A finite element method for the computational modelling of cohesive cracks", Int. J. Numer. Meth. Eng., 63(2), 276-289. https://doi.org/10.1002/nme.1286
  19. Pant, M., Singh, I.V. and Mishra, B.K. (2013), "A novel enrichment criterion for modeling kinked cracks using element free Galerkin method", Int. J. Mech. Sci., 68, 140-149. https://doi.org/10.1016/j.ijmecsci.2013.01.008
  20. Patricio, M. and Mattheij, R. (2007), Crack propagation analysis, CASA Report, 07-03
  21. Rabczuk, T., Bordas, S. and Zi, G. (2007), "A three-dimensional meshfree method for continuous ultiplecrack initiation, propagation and junction in statics and dynamics", Comput. Mech., 40(3), 473-495. https://doi.org/10.1007/s00466-006-0122-1
  22. Rabczuk, T. and Zi, G. (2007), "A meshfree method based on the local partition of unity for cohesive cracks", Comput. Mech., 39(6), 743-760. https://doi.org/10.1007/s00466-006-0067-4
  23. Sukumar, N. and Belytschko, T. (2000), "Arbitrary branched and intersecting cracks with the extended finite element method", Int. J. Numer. Meth. Eng., 48, 1741-1760. https://doi.org/10.1002/1097-0207(20000830)48:12<1741::AID-NME956>3.0.CO;2-L
  24. Sukumar, N., Moes, N., Moran, B. and Belytschko, T. (2000), "Extended finite element method for three-dimensional crack modeling", Int. J. Numer. Meth. Eng., 48(11), 1549-1570. https://doi.org/10.1002/1097-0207(20000820)48:11<1549::AID-NME955>3.0.CO;2-A
  25. Ullah, Z. and Augarde, C.E. (2013), "Finite deformation elasto-plastic modelling using an adaptive meshless method", Comput. Struct., 118, 39-52. https://doi.org/10.1016/j.compstruc.2012.04.001
  26. Wu, Y., Magallanes, J.M., Choi, H.J. and Crawford, J.E. (2012), "Evolutionarily coupled finite-element meshfree formulation for modeling concrete behaviors under blast and impact loadings", J. Eng. Mech., 139(4), 525-536.
  27. Zi, G., Rabczuk, T. and Wall, W. (2007), "Extended meshfree methods without branch enrichment for cohesive cracks", Comput. Mech., 40(2), 367-382. https://doi.org/10.1007/s00466-006-0115-0