×

Finite versus small strain discrete dislocation analysis of cantilever bending of single crystals. (English) Zbl 1381.74173

Summary: Plastic size effects in single crystals are investigated by using finite strain and small strain discrete dislocation plasticity to analyse the response of cantilever beam specimens. Crystals with both one and two active slip systems are analysed, as well as specimens with different beam aspect ratios. Over the range of specimen sizes analysed here, the bending stress versus applied tip displacement response has a strong hardening plastic component. This hardening rate increases with decreasing specimen size. The hardening rates are slightly lower when the finite strain discrete dislocation plasticity (DDP) formulation is employed as curving of the slip planes is accounted for in the finite strain formulation. This relaxes the back-stresses in the dislocation pile-ups and thereby reduces the hardening rate. Our calculations show that in line with the pure bending case, the bending stress in cantilever bending displays a plastic size dependence. However, unlike pure bending, the bending flow strength of the larger aspect ratio cantilever beams is appreciably smaller. This is attributed to the fact that for the same applied bending stress, longer beams have lower shear forces acting upon them and this results in a lower density of statistically stored dislocations.

MSC:

74N05 Crystals in solids
74C05 Small-strain, rate-independent theories of plasticity (including rigid-plastic and elasto-plastic materials)

References:

[1] Hutchinson, J.W.: Plasticity at the micron scale. Int. J. Solids Struct. 37, 225-238 (2000) · Zbl 1075.74022 · doi:10.1016/S0020-7683(99)00090-6
[2] Fleck, N.A., Muller, G.M., Ashby, M.F., et al.: Strain gradient plasticity: theory and experiment. Acta Metal. Mater. 42, 475-487 (1994) · doi:10.1016/0956-7151(94)90502-9
[3] Hall, E.O.: The deformation and ageing of mild steel: III discussion of results. Proc. Phys. Soc. Lond. 64, 747-753 (1951) · doi:10.1088/0370-1301/64/9/303
[4] Petch, N.J.: The cleavage strength of polycrystals. J. Iron Steel Inst. 173, 25-28 (1953)
[5] Deshpande, V.S., Needleman, A., Van der Giessen, E.: Discrete dislocation plasticity analysis of static friction. Acta Mater. 52, 3135-3149 (2004) · doi:10.1016/j.actamat.2004.03.018
[6] Dimiduk, D.M., Uchic, M.D., Parthasarathy, T.A.: Size-affected single-slip behavior of pure nickel microcrystals. Acta Mater. 53, 4065-4077 (2005) · doi:10.1016/j.actamat.2005.05.023
[7] Greer, J.R., Oliver, W.C., Nix, W.D.: Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater. 53, 1821-1830 (2005) · doi:10.1016/j.actamat.2004.12.031
[8] Tang, H., Schwarz, K.W., Espinosa, H.D.: Dislocation escape-related size effects in single-crystal micropillars under uniaxial compression. Acta Mater. 55, 1607-1616 (2007) · doi:10.1016/j.actamat.2006.10.021
[9] Van der Giessen, E., Needleman, A.: Discrete dislocation plasticity: a simple planar model. Model. Simul. Mater. Sci. Eng. 3, 689-735 (1995) · doi:10.1088/0965-0393/3/5/008
[10] Cleveringa, H.H.M., Van der Giessen, E., Needleman, A.: Comparison of discrete dislocation and continuum plasticity predictions for a composite material. Acta Mater. 45, 3163-3179 (1997) · Zbl 0909.73031 · doi:10.1016/S1359-6454(97)00011-6
[11] Cleveringa, H.H.M., Van der Giessen, E., Needleman, A.: A discrete dislocation analysis of bending. Int. J. Plast. 15, 837-868 (1999) · Zbl 0976.74048 · doi:10.1016/S0749-6419(99)00013-3
[12] Balint, D.S., Deshpande, V.S., Needleman, A., et al.: Discrete dislocation plasticity analysis of the wedge indentation of films. J. Mech. Phys. Solids 54, 2281-2303 (2006) · Zbl 1120.74615 · doi:10.1016/j.jmps.2006.07.004
[13] Deshpande, V.S., Needleman, A., Van der Giessen, E.: Plasticity size effects in tension and compression of single crystals. J. Mech. Phys. Solids 53, 2661-2691 (2005) · Zbl 1120.74390 · doi:10.1016/j.jmps.2005.07.005
[14] Danas, K., Deshpande, V.S., Fleck, N.A.: Compliant interfaces: A mechanism for relaxation of dislocation pile-ups in a sheared single crystal. Int. J. Plast. 26, 1792-1805 (2010) · Zbl 1454.74032 · doi:10.1016/j.ijplas.2010.03.008
[15] Cleveringa, H.H.M., Van der Giessen, E., Needleman, A.: A discrete dislocation analysis of mode I crack growth. J. Mech. Phys. Solids 48, 1133-1157 (2000) · Zbl 0984.74076 · doi:10.1016/S0022-5096(99)00076-9
[16] Deshpande, V.S., Needleman, A., Van der Giessen, E.: Discrete dislocation modeling of fatigue crack propagation. Acta Mater. 50, 831-846 (2002) · doi:10.1016/S1359-6454(01)00377-9
[17] Fivel, M.C., Canova, G.R.: Developing rigorous boundary conditions to simulations of discrete dislocation dynamics modelling. Model. Simul. Mater. Sci. Eng. 7, 753-768 (1999) · doi:10.1088/0965-0393/7/5/308
[18] Benzerga, A.A., Bréchet, Y., Needleman, A., et al.: Incorporating three-dimensional mechanisms into two-dimensional dislocation dynamics. Model. Simul. Mater. Sci. Eng. 12, 159-196 (2003) · doi:10.1088/0965-0393/12/1/014
[19] Yasin, H., Zbib, H.M., Khaleel, M.A.: Size and boundary effects in discrete dislocation dynamics: coupling with continuum finite element. Mater. Sci. Eng. A 309, 294-299 (2001) · doi:10.1016/S0921-5093(00)01731-7
[20] Vattré, A., Devincre, B., Feyel, F., et al.: Modelling crystal plasticity by 3d dislocation dynamics and the finite element method: the discrete-continuous model revisited. J. Mech. Phys. Solids 63, 491-505 (2014) · doi:10.1016/j.jmps.2013.07.003
[21] Prasad Reddy, G.V., Robertson, C., Déprés, C., et al.: Effect of grain disorientation on early fatigue crack propagation in face-centred-cubic polycrystals: A three-dimensional dislocation dynamics investigation. Acta Mater. 61, 5300-5310 (2013) · doi:10.1016/j.actamat.2013.05.021
[22] Senger, J., Weygand, D., Gumbsch, P., et al.: Discrete dislocation simulations of the plasticity of micro-pillars under uniaxial loading. Scr. Mater. 58, 587-590 (2008) · doi:10.1016/j.scriptamat.2007.11.031
[23] Šiška, F., Weygand, D., Forest, S., et al.: Comparison of mechanical behaviour of thin film simulated by discrete dislocation dynamics and continuum crystal plasticity. Comput. Mater. Sci. 45, 793-799 (2009) · doi:10.1016/j.commatsci.2008.07.006
[24] Fivel, M.C., Robertson, C.F., Canova, G.R., et al.: Three-dimensional modeling of indent-induced plastic zone at a mesoscale. Acta Mater. 46, 6183-6194 (1998) · doi:10.1016/S1359-6454(98)00278-X
[25] Khraishi, T.A., Zbib, H.M., de La Rubia, T.D., et al.: Localized deformation and hardening in irradiated metals: three-dimensional discrete dislocation dynamics simulations. Metal. Mater. Trans. B 33, 285-296 (2002) · doi:10.1007/s11663-002-0012-7
[26] Déprés, C., Prasad Reddy, G.V., Robertson, C., et al.: An extensive 3d dislocation dynamics investigation of stage-i fatigue crack propagation. Philos. Mag. 94, 4115-4137 (2014) · doi:10.1080/14786435.2014.978830
[27] Stölken, J.S., Evans, A.G.: A microbend test method for measuring the plasticity length scale. Acta Mater. 46, 5109-5115 (1998) · doi:10.1016/S1359-6454(98)00153-0
[28] Motz, C., Schöberl, T., Pippan, R.: Mechanical properties of micro-sized copper bending beams machined by the focused ion beam technique. Acta Mater. 53, 4269-4279 (2005)
[29] Motz, C., Weygand, D., Senger, J., et al.: Micro-bending tests: a comparison between three-dimensional discrete dislocation dynamics simulations and experiments. Acta Mater. 56, 1942-1955 (2008) · doi:10.1016/j.actamat.2007.12.053
[30] Danas, K., Deshpande, V.S.: Plane-strain discrete dislocation plasticity with climb-assisted glide motion of dislocations. Model. Simul. Mater. Sci. Eng. 21, 045008 (2013) · doi:10.1088/0965-0393/21/4/045008
[31] Tarleton, E., Balint, D.S., Gong, J., Wilkinson, A.J.: A discrete dislocation plasticity study of the micro-cantilever size effect. Acta Mater. 88, 271-282 (2015) · doi:10.1016/j.actamat.2015.01.030
[32] Irani, N., Remmers, J.J.C., Deshpande, V.S.: Finite strain discrete dislocation plasticity in a total Lagrangian setting. J. Mech. Phys. Solids 83, 160-178 (2015) · doi:10.1016/j.jmps.2015.06.013
[33] Deshpande, V.S., Needleman, A., Van der Giessen, E.: Finite strain discrete dislocation plasticity. J. Mech. Phys. Solids 51, 2057-2083 (2003) · Zbl 1041.74504 · doi:10.1016/j.jmps.2003.09.012
[34] Kubin, L.P., Canova, G., Condat, M., et al.: Dislocation microstructures and plastic flow: a 3d simulation. Solid State Phenom. 23-24, 455-472 (1992) · doi:10.4028/www.scientific.net/SSP.23-24.455
[35] Balint, D.S., Deshpande, V.S., Needleman, A., et al.: Size effects in uniaxial deformation of single and polycrystals: a discrete dislocation plasticity analysis. Modell. Simul. Mater. Sci. Eng. 14, 409-422 (2006) · Zbl 1075.74022
[36] Nye, J.F.: Some geometrical relations in dislocated crystals. Acta Metal. 1, 153-162 (1953) · doi:10.1016/0001-6160(53)90054-6
[37] Fleck, N.A., Hutchinson, J.W.: Strain gradient plasticity. Adv. Appl. Mech. 33, 295-361 (1997) · Zbl 0894.73031 · doi:10.1016/S0065-2156(08)70388-0
[38] Forest, S., Cailletaud, G., Sievert, R.: A Cosserat theory for elastoviscoplastic single crystals at finite deformation. Arch. Mech. 49, 705-736 (1997) · Zbl 0893.73023
[39] Sandfeld, S., Hochrainer, T., Gumbsch, P., et al.: Numerical implementation of a 3D continuum theory of dislocation dynamics and application to micro-bending. Philos. Mag. 90, 3697-3728 (2010) · doi:10.1080/14786430903236073
[40] Le, K.C., Nguyen, B.D.: On bending of single crystal beam with continuously distributed dislocations. Int. J. Plast. 48, 152-167 (2013) · doi:10.1016/j.ijplas.2013.02.010
[41] Le, K.C., Nguyen, B.D.: Polygonization as low energy dislocation structure. Contin. Mech. Thermodyn. 22, 291-298 (2010) · Zbl 1234.74011 · doi:10.1007/s00161-010-0137-x
[42] Le, K.C., Nguyen, B.D.: Polygonization: theory and comparison with experiments. Int. J. Eng. Sci. 59, 211-218 (2012) · doi:10.1016/j.ijengsci.2012.03.005
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.