Abstract
Blind analyses of the localization and ductile fracture behavior of an arbitrarily shaped coupon, performed for the Sandia Fracture Challenge, are presented. These analyses were performed using a shear-modified Gurson porous plasticity model that was calibrated using standard mechanical test data. The blind predictions were found to be in good agreement with experimental data, thus increasing confidence in the calibration methodology where test data is not available. In addition to the analyses submitted to the Challenge, additional non-blind analyses examining the role of both as-machined versus nominal coupon geometry and the selected value of initial porosity were conducted. It was found that by capturing the as-machined, out of tolerance, geometry in numerical calculations the fracture mode was altered from tension to shear. This agrees well with the experimental observation that all in-tolerance coupons failed in a tensile mode while all out-of-tolerance coupons failed in a shear mode. Additionally, it was found that by modifying the initial void volume fraction to a lower value still within the range that the calibration methodology provided, calculations capturing this as-machined geometry were able to closely match experimental results.
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References
Alsos HS, Amdahl J (2009) On the resistance to penetration of stiffened plates, part I—experiments. Int J Impact Eng 36:799–807. doi:10.1016/j.ijimpeng.2008.10.005
Alsos HS, Amdahl J, Hopperstad OS (2009) On the resistance to penetration of stiffened plates, part II: numerical analysis. Int J Impact Eng 33:875–887. doi:10.1016/j.ijimpeng.2008.11.004
Bao Y, Wierzbicki T (2004) On fracture locus in the equivalent strain and stress triaxiality space. Int J Mech Sci 46:81–98. doi:10.1016/j.ijmecsci.2004.02.006
Barsoum I, Faleskog J, Pingle S (2012) The effect of stress state on ductility in the moderate stress triaxiality regime of medium and high strength steels. Int J Mech Sci 65:203–212. doi:10.1016/j.ijmecsci.2012.10.003
Boyce BL, Kramer SLB, Fang HE et al (2013) The Sandia Fracture challenge: blind round robin predictions of ductile tearing. Int J Fract. doi:10.1007/s10704-013-9904-6
Dunand M, Mohr D (2010) Hybrid experimental-numerical analysis of basic ductile fracture experiments for sheet metals. Int J Solids Struct 47:1130–1143. doi:10.1016/j.ijsolstr.2009.12.011
Flanagan DP, Belytschko T (1981) A uniform strain hexahedron and quadrilateral with orthogonal hourglass control. Int J Numer Methods Eng 17:679–706. doi:10.1002/nme.1620170504
Geffroy A-G, Longère P, Leblé B (2011) Fracture analysis and constitutive modelling of ship structure steel behaviour regarding explosion. Eng Fail Anal 18:670–681. doi:10.1016/j.engfailanal.2010.09.038
Gullerud AS, Gao X, Dodds RH, Haj-Ali R (2000) Simulation of ductile crack growth using computational cells: numerical aspects. Eng Fract Mech 66:65–92
Guo J, Zhao S, Murakami R, Zang S (2013) Experimental and numerical investigation for ductile fracture of Al-alloy 5052 using modified Rousselier model. Comput Mater Sci 71:115–123. doi:10.1016/j.commatsci.2013.01.011
Gurson AL (1977) Continuum theory of ductile rupture by void nucleation and growth: part I-yield criteria and flow rules for porous ductile media. J Eng Mater Technol 99:2. doi:10.1115/1.3443401
Johnson GR, Cook WH (1985) Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures. Eng Fract Mech 21:31–48. doi:10.1016/0013-7944(85)90052-9
Koppenhoefer KC, Dodds RH (1998) Ductile crack growth in pre-cracked CVN specimens: numerical studies. Nucl Eng Des 180:221–241. doi:10.1016/S0029-5493(97)00218-5
Nahshon K, Hutchinson JW (2008) Modification of the Gurson model for shear failure. Eur J Mech A Solids 27:1–17. doi:10.1016/j.euromechsol.2007.08.002
Nahshon K, Xue Z (2009) A modified Gurson model and its application to punch-out experiments. Eng Fract Mech 76:997–1009. doi:10.1016/j.engfracmech.2009.01.003
Ruggieri C, Dotta F (2011) Numerical modeling of ductile crack extension in high pressure pipelines with longitudinal flaws. Eng Struct 33:1423–1438. doi:10.1016/j.engstruct.2011.01.001
Simonsen BC, Törnqvist R (2004) Experimental and numerical modeling of ductile crack propagation in large-scale shell structures. Mar Struct 17:1–27. doi:10.1016/j.marstruc.2004.03.004
Tvergaard V (1981) Influence of voids on shear band instabilities under plane strain conditions. Int J Fract 17:389–407. doi:10.1007/BF00036191
Tvergaard V (1982) On localization in ductile materials containing spherical voids. Int J Fract 18:237–252
Tvergaard V, Needleman A (1984) Analysis of the cup-cone fracture in a round tensile bar. Acta Metall 32:157–169. doi:10.1016/0001-6160(84)90213-X
Xue Z, Pontin MG, Zok FW, Hutchinson JW (2010) Calibration procedures for a computational model of ductile fracture. Eng Fract Mech 77:492–509. doi:10.1016/j.engfracmech.2009.10.007
Acknowledgments
Financial support provided by the Office of Naval Research Structural Reliability Program, under the direction of Dr. Paul Hess (Document #N0001413WX20603), and the High Performance Computing Modernization Office CREATE Program is gratefully acknowledged. In addition, the authors would like to thank the Sandia National Labs SIERRA Structural Mechanics team for providing extensive support and validation assistance with the SIERRA/SM VUMAT interface.
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Nahshon, K., Miraglia, M., Cruce, J. et al. Prediction of the Sandia Fracture Challenge using a shear modified porous plasticity model. Int J Fract 186, 93–105 (2014). https://doi.org/10.1007/s10704-013-9909-1
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DOI: https://doi.org/10.1007/s10704-013-9909-1