Artículos de revistas: "Void growth and coalescence"

1

Klassen, R. J., G. C. Weatherly y B. Ramaswami. "Void growth and coalescence". Metallurgical Transactions A 23, S1 (diciembre de 1992): 3273–80. http://dx.doi.org/10.1007/bf03024534.

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2

Ma, Dong Fang, Gao Tao Deng, Da Nian Chen, Shan Xing Wu y Huan Ran Wang. "A Visualized Investigation of Void Growth and Coalescence in Pure Copper Sheets under Impact Tension". Advanced Materials Research 317-319 (agosto de 2011): 1717–24. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1717.

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The multi-tension loading in the optimized tensile split Hopkinson bar tests for pure copper sheets was used to investigating growth and coalescence of drilled voids in pure copper sheets, recorded by a high-speed camera. The results of scanning electron microscopical investigation of the microvoid evolution in recovered pure copper sheets showed void coalescence mechanisms which are similar to that of visualized drilled voids. The semi-empirical relation [8] for void shape evolution under quasi-static tension was compared with our computed results revealing the dynamic and clustering effects on void growth. The possibility of application of Thomason model[9] and Considere’s condition[10] for void coalescence to thermoviscoplatic constitutive model was explored under impact tension. The main effects affecting dynamic growth and coalescence of voids were presented including the geometry (void size, shape, orientation, spacing), the material properties (dynamic constitutive model) and the stress state (impact tension condition).

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3

Rao, U. S. y R. C. Chaturvedi. "Sheet Metal Forming Limits Under Complex Strain Paths Using Void Growth and Coalescence Model". Journal of Engineering Materials and Technology 108, n.º 3 (1 de julio de 1986): 240–44. http://dx.doi.org/10.1115/1.3225875.

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It is well established that ductile fracture occurs by nucleation, growth and coalescence of voids. Several models have been developed to predict limits under constant strain ratio paths considering void inhomogeneity and void growth. In this paper the void growth and coalescence model developed by Rao and Chaturvedi for predicting forming limits under constant strain ratio paths, has been extended for predicting forming limits under two stage strain paths. The predicted results have been compared with experimental results of Ishigaki and analyzed.

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4

Tsuji, Tomoaki. "The Void Growth Simulations in the Hyper-Elastic Material with Multiple Seeds". Materials Science Forum 502 (diciembre de 2005): 45–50. http://dx.doi.org/10.4028/www.scientific.net/msf.502.45.

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The behaviors of a material are nonlinear in the large deformed region. The hyper elastic models can describe such non linear materials. If the hyper elastic material is applied to the hydrostatic tensile load, the void begins to grow when the load exceed the critical value. It is important to study the coalescence of the void growth in order to consider the destruction of the material. In this paper, the void growth simulations in the hyper-elastic material with multiple seeds are studied. The unit rectangular cell with small voids is subjected to the hydrostatic tensile load. This problem can be analyzed by FEM. However, the simulation with the larger number of the voids is not possible. Thus, the CA (Cellular Automaton) is used to describe the behaviors of the void coalescence and the possibility of CA is discussed.

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5

WONG, W. H., T. F. GUO y L. CHENG. "VOID GROWTH AND INTERACTION IN A SOFT MATERIAL". International Journal of Modern Physics B 24, n.º 01n02 (20 de enero de 2010): 295–304. http://dx.doi.org/10.1142/s021797921006423x.

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Void growth and interaction in a soft material is explored numerically in this work in a three-dimensional context. Discrete initially spherical voids are explicitly modeled ahead of a crack front under small-scale yielding. While a multiple void interaction mechanism can be identified in our study, computations show a qualitatively similar void growth exhibited for the initial void volume fractions considered, f0 = 0.1% and 1%. Extensive void growth in the damage process zone are observed upon application of load, with the resultant deformed voids taking on a prolated void shape. A micromechanical analysis of void growth is also carried out and the numerical results suggest a failure mechanism in the soft material not attributed to void coalescence but by a mechanism analogous to tearing.

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6

Jones, M. K., M. F. Horstemeyer y A. D. Belvin. "A Multiscale Analysis of Void Coalescence in Nickel". Journal of Engineering Materials and Technology 129, n.º 1 (9 de junio de 2006): 94–104. http://dx.doi.org/10.1115/1.2400265.

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An internal state variable void coalescence equation developed by Horstemeyer, Lathrop, Gokhale, and Dighe (2000, Theor. Appl. Fract. Mech., 33(1), pp. 31–47) that comprises void impingement and void sheet mechanisms is updated based on three-dimensional micromechanical simulations and novel experiments. This macroscale coalescence equation, developed originally from two-dimensional finite element simulations, was formulated to enhance void growth. In this study, three-dimensional micromechanical finite element simulations were employed using cylindrical and spherical void geometries in nickel that were validated by experiments. The number of voids, void orientation, and void spacing were all varied and tested and simulated under uniaxial loading conditions. The micromechanical results showed excellent agreement with experiments in terms of void volume fractions versus strain and local void geometry images. Perhaps more importantly, the macroscale internal state variable void coalescence equation did not require a functional form change but just a coefficient value modification.

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7

Chen, Jie, Darby J. Luscher y Saryu J. Fensin. "The Modified Void Nucleation and Growth Model (MNAG) for Damage Evolution in BCC Ta". Applied Sciences 11, n.º 8 (9 de abril de 2021): 3378. http://dx.doi.org/10.3390/app11083378.

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A void coalescence term was proposed as an addition to the original void nucleation and growth (NAG) model to accurately describe void evolution under dynamic loading. The new model, termed as modified void nucleation and growth model (MNAG model), incorporated analytic equations to explicitly account for the evolution of the void number density and the void volume fraction (damage) during void nucleation, growth, as well as the coalescence stage. The parameters in the MNAG model were fitted to molecular dynamics (MD) shock data for single-crystal and nanocrystalline Ta, and the corresponding nucleation, growth, and coalescence rates were extracted. The results suggested that void nucleation, growth, and coalescence rates were dependent on the orientation as well as grain size. Compared to other models, such as NAG, Cocks–Ashby, Tepla, and Tonks, which were only able to reproduce early or later stage damage evolution, the MNAG model was able to reproduce all stages associated with nucleation, growth, and coalescence. The MNAG model could provide the basis for hydrodynamic simulations to improve the fidelity of the damage nucleation and evolution in 3-D microstructures.

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8

Tekoğlu, C., J. W. Hutchinson y T. Pardoen. "On localization and void coalescence as a precursor to ductile fracture". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 373, n.º 2038 (28 de marzo de 2015): 20140121. http://dx.doi.org/10.1098/rsta.2014.0121.

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Two modes of plastic flow localization commonly occur in the ductile fracture of structural metals undergoing damage and failure by the mechanism involving void nucleation, growth and coalescence. The first mode consists of a macroscopic localization, usually linked to the softening effect of void nucleation and growth, in either a normal band or a shear band where the thickness of the band is comparable to void spacing. The second mode is coalescence with plastic strain localizing to the ligaments between voids by an internal necking process. The ductility of a material is tied to the strain at macroscopic localization, as this marks the limit of uniform straining at the macroscopic scale. The question addressed is whether macroscopic localization occurs prior to void coalescence or whether the two occur simultaneously. The relation between these two modes of localization is studied quantitatively in this paper using a three-dimensional elastic–plastic computational model representing a doubly periodic array of voids within a band confined between two semi-infinite outer blocks of the same material but without voids. At sufficiently high stress triaxiality, a clear separation exists between the two modes of localization. At lower stress triaxialities, the model predicts that the onset of macroscopic localization and coalescence occur simultaneously.

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9

Banabic, Dorel y Abdolvahed Kami. "Applications of the Gurson’s model in sheet metal forming". MATEC Web of Conferences 190 (2018): 01002. http://dx.doi.org/10.1051/matecconf/201819001002.

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Recent advances in the modelling of metals encompass modelling of metals structural inhomogeneity, damage, porosity, twinning/untwining and non-local and second order effects. This presentation is focused on modelling the void growth in ductile fractures. The growth and coalescence of microscopic voids are the main mechanisms in ductile fracture of bulk metallic parts. In sheet metals, ductile fracture is preceded by necking during which existing voids do not have significant growth. However, necking is highly sensitive to plastic flow direction which in turn is sensitive to the presence of voids. Also, under biaxial strain loading, the final fracture in the necking region is still controlled by void growth; hence an accurate fracture prediction is crucial for crash simulations. Finally, in super-plastic sheet forming, void growth and coalescence may precede or accompany necking. Therefore, there is as increasing interest in modelling of voids in the sheet metals. As an application, we show how the predictions of some forming limit curves (FLCs) can be affected by accurate simulation of voids growth.

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10

Wang, Yong Gang, Hong Liang He, Li Li Wang y Fu Qian Jing. "Percolation-Relaxation Model with Critical Damage for Describing the Dynamic Tensile Spall of Ductile Metals". Key Engineering Materials 324-325 (noviembre de 2006): 121–24. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.121.

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In the framework of percolation theory, a simple void-coalescence model combined with the constitutive relations for describing the stress relaxation and material softening during the void-coalescence process, name as the percolation-relaxation (P-R) model, is proposed to describe the dynamic tensile spallation of ductile metals. A critical damage is introduced and coupled into the model to identify the onset of the void coalescence. Mesoscopically, the critical damage corresponds to the critical intervoid ligament distance (ILD), indicating the start of transition from the void-growth to the void-coalescence.

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11

Worswick, M. J., H. Nahme y J. Fowler. "Spall through void nucleation, growth and coalescence". Le Journal de Physique IV 04, n.º C8 (septiembre de 1994): C8–623—C8–628. http://dx.doi.org/10.1051/jp4:1994894.

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12

Yerra, S. K., C. Tekog˜lu, F. Scheyvaerts, L. Delannay, P. Van Houtte y T. Pardoen. "Void growth and coalescence in single crystals". International Journal of Solids and Structures 47, n.º 7-8 (abril de 2010): 1016–29. http://dx.doi.org/10.1016/j.ijsolstr.2009.12.019.

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13

Lee, J. H. y Y. Zhang. "A Finite-Element Work-Hardening Plasticity Model of the Uniaxial Compression and Subsequent Failure of Porous Cylinders Including Effects of Void Nucleation and Growth—Part I: Plastic Flow and Damage". Journal of Engineering Materials and Technology 116, n.º 1 (1 de enero de 1994): 69–79. http://dx.doi.org/10.1115/1.2904257.

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Gurson’s mixed hardening plasticity model (which takes into account the progressive damage due to void nucleation and growth of an initially dense material), with strain and stress-controlled nucleations, was used in a large deformation finite element program to study the plastic flow and damage in the uniaxial compression of cylinders under sticking friction. Effects of strain hardening, nucleation models, yield surface curvature, and geometry on the distributions and evolutions of stresses, strains, mean stress, void fractions, and coalescence are studied in detail. Using Gurson’s isotropic hardening model, positive mean and axial stresses developed at the bulge of the cylinder with growth of voids at latter stages of deformation. Due low stress triaxiality (Σm/σe<0.6) at the bulge, the process is nucleation rather than growth dominated for the majority of the cases studied. At failure, the maximum void fraction at the bulge among all cases studied is 0.085 and is far less than the critical void fraction (≈0.15) for coalescence.

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14

Benzerga, A. A., J. Besson y A. Pineau. "Coalescence-Controlled Anisotropic Ductile Fracture". Journal of Engineering Materials and Technology 121, n.º 2 (1 de abril de 1999): 221–29. http://dx.doi.org/10.1115/1.2812369.

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The anisotropic ductile fracture of rolled plates containing elongated inclusions is promoted by both the dilational growth of voids and the coalescence process. In the present article, the emphasis is laid on the latter process. The effects of void shape and mainly of inter-particle spacings are investigated. Two types of coalescence models are compared: a localization-based model and plastic limit-load models. The capabilities of both approaches to incorporate shape change and spacing effects are discussed. These models are used to predict the fracture properties of two low alloy steels containing mainly manganese sulfide inclusions. Both materials are characterized in different loading directions. Microstructural data inferred from quantitative metallography are used to derive theoretical values of critical void volume fractions at incipient coalescence. These values are used in FE-calculations of axisymmetrically notched specimens with different notch radii and loading directions.

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15

Pardoen, T. y J. W. Hutchinson. "An extended model for void growth and coalescence". Journal of the Mechanics and Physics of Solids 48, n.º 12 (diciembre de 2000): 2467–512. http://dx.doi.org/10.1016/s0022-5096(00)00019-3.

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16

Surh, Michael P., Jess B. Sturgeon y Wilhelm G. Wolfer. "Void nucleation, growth, and coalescence in irradiated metals". Journal of Nuclear Materials 378, n.º 1 (agosto de 2008): 86–97. http://dx.doi.org/10.1016/j.jnucmat.2008.05.009.

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17

Ha, Sangyul y KiTae Kim. "Void growth and coalescence in f.c.c. single crystals". International Journal of Mechanical Sciences 52, n.º 7 (julio de 2010): 863–73. http://dx.doi.org/10.1016/j.ijmecsci.2010.03.001.

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18

Klassen, R. J., G. C. Weatherly y B. Ramaswami. "Void growth and coalescence in constrained silver interlayers". Metallurgical Transactions A 23, n.º 12 (diciembre de 1992): 3273–80. http://dx.doi.org/10.1007/bf02663436.

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19

Worswick, M. J. y R. J. Pick. "Void growth and coalescence during high velocity impact". Mechanics of Materials 19, n.º 4 (febrero de 1995): 293–309. http://dx.doi.org/10.1016/0167-6636(94)00041-e.

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20

Keralavarma, S. M., S. Hoelscher y A. A. Benzerga. "Void growth and coalescence in anisotropic plastic solids". International Journal of Solids and Structures 48, n.º 11-12 (junio de 2011): 1696–710. http://dx.doi.org/10.1016/j.ijsolstr.2011.02.020.

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21

Koplik, J. y A. Needleman. "Void growth and coalescence in porous plastic solids". International Journal of Solids and Structures 24, n.º 8 (1988): 835–53. http://dx.doi.org/10.1016/0020-7683(88)90051-0.

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22

Trejo Navas, Victor Manuel, Marc Bernacki y Pierre-Olivier Bouchard. "Void growth and coalescence in a three-dimensional non-periodic void cluster". International Journal of Solids and Structures 139-140 (mayo de 2018): 65–78. http://dx.doi.org/10.1016/j.ijsolstr.2018.01.024.

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23

Zaporozhets, T. V., I. V. Sobchenko y Andriy Gusak. "3D-Simulation of Void Formation, Growth and Migration under Electromigration". Defect and Diffusion Forum 237-240 (abril de 2005): 1306–11. http://dx.doi.org/10.4028/www.scientific.net/ddf.237-240.1306.

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The 3D Monte Carlo scheme is proposed for simulation of simultaneous self-consistent current redistribution, surface diffusion, drift and void migration and coalescence at the interface metal/dielectric. Results of simulation as well as simple phenomenological model demonstrate a possibility of trapping at and migration along the grainboundaries (GBs). Critical size of “detrapping” after coalescence has been estimated.

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24

Fukahori, Tomoaki, Shinichi Suzuki, Naoya Yamada, Masatoshi Aramaki y Osamu Furukimi. "Effect of Microstructure on Formation of Ductile Fracture Surface in Steel Plate". Advanced Materials Research 409 (noviembre de 2011): 678–83. http://dx.doi.org/10.4028/www.scientific.net/amr.409.678.

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In recent years, high strength steel plates for building and pipelines have been required to improve ductile fracture properties, assuming ground deformation in earthquake-prone region. The ductile fracture is performed by the result from coalescence of micro-voids followed by the nucleation and growth [1]. Fractured surface morphology reflects the void coalescence process, so it is important to consider the relationship between the fracture surface morphology and the micro-voids formation beneath the fractured surface to consider the ductile fracture properties. The voids nucleate sites are mainly particles such as inclusions or precipitates, and grain boundries. These voids grow and coalesce according to three modes. The first mode is directly coalescence of voids followed by growth [2]. The second one is the coalescence of voids caused by shear deformation followed by internal necking between voids [3]. The third one is the coalescence of voids caused by micro-voids nucleation in shear band between two larger voids [4]. It is expected that these modes influence local elongation property which is one of the indices for ductile fracture property through the formation of fractured surface. In this study, local deformation energy which is measured by load-displacement curve in tensile test is examined by focusing the voids nucleation, growth and coalescence, for high tensile strength plates of TS480-830MPa which is controlled by the microstructure through the cooling rate of heat treatment. The deformation energy is useful to consider the ductile fracture property of steel plates which have a different tensile strength.

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25

GROH, SEBASTIEN, ESTEBAN B. MARIN y M. F. HORSTEMEYER. "NANOSCALE VOID GROWTH IN MAGNESIUM: A MOLECULAR DYNAMICS STUDY". International Journal of Applied Mechanics 02, n.º 01 (marzo de 2010): 191–205. http://dx.doi.org/10.1142/s1758825110000421.

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Molecular dynamics calculations were carried out in single crystal magnesium specimens to reveal the dependence of strain rate, temperature, and orientation of the crystal on damage evolution as defined by pore growth. Two specific crystallographic orientations [0001] and [Formula: see text] were examined. During a [0001] tensile test, twin boundaries developed at the void surface leading to a constraint on the [Formula: see text] crystallographic orientation. On the other hand, during the [Formula: see text] tensile deformation, emission of shear loops in the prismatic slip planes arose when void growth initiated. Furthermore, analysis of the damage components (nucleation, growth and coalescence) revealed that a large number of small voids nucleated that rapidly grew and fractured the specimens independent of the temperature and the strain rate.

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26

Selvarajou, Balaji, Shailendra P. Joshi y A. Amine Benzerga. "Void growth and coalescence in hexagonal close packed crystals". Journal of the Mechanics and Physics of Solids 125 (abril de 2019): 198–224. http://dx.doi.org/10.1016/j.jmps.2018.12.012.

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27

Barrioz, P. O., J. Hure y B. Tanguy. "Void growth and coalescence in irradiated copper under deformation". Journal of Nuclear Materials 502 (abril de 2018): 123–31. http://dx.doi.org/10.1016/j.jnucmat.2018.01.064.

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28

Niordson, Christian F. "Void growth to coalescence in a non-local material". European Journal of Mechanics - A/Solids 27, n.º 2 (marzo de 2008): 222–33. http://dx.doi.org/10.1016/j.euromechsol.2007.07.001.

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29

Steglich, Dirk, Husam Wafai y Jacques Besson. "Anisotropic Plastic Deformation and Damage in Commercial Al 2198 T8 Sheet Metal". Key Engineering Materials 452-453 (noviembre de 2010): 97–100. http://dx.doi.org/10.4028/www.scientific.net/kem.452-453.97.

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Deformation anisotropy of sheet aluminium alloy 2198 (Al-Cu-Li) has been investigated by means of mechanical testing of notched specimens and Kahn-type fracture specimens, loaded in the rolling direction (L) or in the transverse direction (T). Contributions to failure are identified as growth of initial voids accompanied by a significant nucleation of a second population of cavities and transgranular failure. A model based on the Gurson-Tvergaard-Needleman (GTN) approach of porous metal plasticity incorporating isotropic voids, direction-dependent void growth, void nucleation at a second population of inclusions and triaxiality-dependent void coalescence has been used to predict the mechanical response of test samples. The model has been successfully used to describe and predict the direction-dependent deformation behaviour, crack propagation and, in particular, toughness anisotropy.

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30

Nemcko, Michael J., Jing Li y David S. Wilkinson. "Effects of void band orientation and crystallographic anisotropy on void growth and coalescence". Journal of the Mechanics and Physics of Solids 95 (octubre de 2016): 270–83. http://dx.doi.org/10.1016/j.jmps.2016.06.003.

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31

Tvergaard, Viggo. "Discrete modelling of ductile crack growth by void growth to coalescence". International Journal of Fracture 148, n.º 1 (noviembre de 2007): 1–12. http://dx.doi.org/10.1007/s10704-007-9172-4.

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32

Vu, Cong Hoa, Do Won Seo y Jae Kyoo Lim. "Analysis of Spherical Void Growth and Coalescence in Metal Plastic Straining Process". Key Engineering Materials 297-300 (noviembre de 2005): 2837–42. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.2837.

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Ductile fracture occurs due to micro-void nucleation, growth and finally coalescence into micro-crack. In this study a new ductile fracture condition that based on the microscopic phenomena of void nucleation, growth and coalescence was proposed. Using this condition and combining with finite element model to predict the fracture locations in bulk metal forming. The macroscopic behavior of the material is described according to the flow rules of Levy-Mises. An idealized spherical void within an finite matrix is assumed. The void volume is calculated by taking the increasing volume of the continuum, caused by plastic straining, incorporated in the yield functions. In the model there includes the strain-hardening coefficient of the Ludwik-Holomom stress-strain relationship and concentration of stress. The accumulated damage value is a phenomenon in this model. The results show that it is in close accordance with observations of some experimental specimens. However, in order to obtaining the high trustiness many experiments have to be carried out.

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33

Zapara, Maksim, Nikolai Tutyshkin y Wolfgang H. Müller. "Growth and Closure of Voids in Metals at Negative Stress Triaxialities". Key Engineering Materials 554-557 (junio de 2013): 1125–32. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.1125.

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Damage of metals subjected to large plastic deformations typical for forming processes is mainly governed by void nucleation, growth and coalescence. An opposite process may occur in deformation processes with negative stress triaxialities: the closure of strain-induced defects under large hydrostatic pressure. Understanding the mechanisms of damage growth and healing under plastic deformation of metals is still an urgent problem. In order to solve it a theoretical framework for anisotropic ductile damage based on a physically motivated concept for changes in the void volume and shape was recently developed [6]. Strain-induced damage was experimentally determined during uniaxial compression of cylindrical metallic specimens with artificial voids represented by fully-trough drilled holes. It was revealed that the governing physical mechanism of failure is a change in void shapes due to compressive stresses at low negative stress triaxialities in contrast to the growth of voids volume due to high positive stress triaxialities in the processes with dominating tensile stresses. The tensorial model presented in [6] proved to be able to describe kinetics of ductile damage, failure as the ultimate damage, and the closure of voids at negative stress triaxialities.

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34

Reffas, S. A., M. Elmeguenni y M. Benguediab. "Analysis of Void Growth and Coalescence in Porous Polymer Materials. Coalescence in Polymer Materials". Engineering, Technology & Applied Science Research 3, n.º 3 (3 de junio de 2013): 452–60. http://dx.doi.org/10.48084/etasr.330.

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The use of polymeric materials in engineering applications is growing more and more all over the world. This issue requests new methodologies of analysis in order to assess the material’s capability to withstand complex loads. The use of polyacetal in engineering applications has increased rapidly in the last decade. In order to evaluate the behavior, the damage and coalescence of this type of polymer, a numerical method based on damage which occurs following several stages (nucleation of cavities, their growth and coalescence in more advanced stages of deformation) is proposed in this work. A particular attention is given on the stress-strain and the volumetric strain evolution under different triaxiality and for three initial void shapes. Its application to polyacetal allows approving this approach for technical polymers. Finally, this method allow us to compare the obtained results of basic calculations at different triaxiality and to discuss their possible influence on the initial size and the geometrical shape of the porosity on the material failure.

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35

Bandstra, J. P. y D. A. Koss. "On the influence of void clusters on void growth and coalescence during ductile fracture". Acta Materialia 56, n.º 16 (septiembre de 2008): 4429–39. http://dx.doi.org/10.1016/j.actamat.2008.05.009.

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36

Linder, David, Jia-Yi Yan, Martin Walbrühl, John Ågren y Annika Borgenstam. "Modeling confined ductile fracture – A void-growth and coalescence approach". International Journal of Solids and Structures 202 (octubre de 2020): 454–62. http://dx.doi.org/10.1016/j.ijsolstr.2020.06.039.

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37

Dung, Nguyen Luong. "Plasticity theory of ductile fracture by void growth and coalescence". Forschung im Ingenieurwesen 58, n.º 5 (mayo de 1992): 135–40. http://dx.doi.org/10.1007/bf02561501.

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38

Horstemeyer, M. F., M. M. Matalanis, A. M. Sieber y M. L. Botos. "Micromechanical finite element calculations of temperature and void configuration effects on void growth and coalescence". International Journal of Plasticity 16, n.º 7-8 (junio de 2000): 979–1015. http://dx.doi.org/10.1016/s0749-6419(99)00076-5.

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39

Ha, Sang-Yul y Ki-Tae Kim. "Study on the Void Growth and Coalescence in F.C.C. Single Crystals". Transactions of the Korean Society of Mechanical Engineers A 32, n.º 4 (1 de abril de 2008): 319–26. http://dx.doi.org/10.3795/ksme-a.2008.32.4.319.

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40

Selvarajou, Balaji, Shailendra P. Joshi y A. Amine Benzerga. "Corrigendum to “Void growth and coalescence in hexagonal close packed crystals”". Journal of the Mechanics and Physics of Solids 125 (abril de 2019): 825–27. http://dx.doi.org/10.1016/j.jmps.2019.01.011.

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41

Mi, Changwen, Daniel A. Buttry, Pradeep Sharma y Demitris A. Kouris. "Atomistic insights into dislocation-based mechanisms of void growth and coalescence". Journal of the Mechanics and Physics of Solids 59, n.º 9 (septiembre de 2011): 1858–71. http://dx.doi.org/10.1016/j.jmps.2011.05.008.

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42

Zanganeh, M., C. Pinna y JR Yates. "Void growth and coalescence modelling in AA2050 using the Rousselier model". International Journal of Damage Mechanics 22, n.º 2 (27 de marzo de 2012): 219–37. http://dx.doi.org/10.1177/1056789512441808.

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In this study, the damage evolution process in an AA2050 aluminium alloy is studied under various triaxiality levels using notched tensile specimens. The performance of the Rousselier model is assessed and it is shown that modifications are required both in the hardening curve and the damage evolution parts of the model in order to match the experimental results. The original model is corrected by adding the effect of hydrostatic pressure on the yield surface as well as implementing the Thomason coalescence model. The transferability of the Rousselier model parameters to other triaxiality levels is investigated and a procedure to identify these parameters is proposed.

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43

AHN, D., P. SOFRONIS y R. DODDSJR. "On hydrogen-induced plastic flow localization during void growth and coalescence". International Journal of Hydrogen Energy 32, n.º 16 (noviembre de 2007): 3734–42. http://dx.doi.org/10.1016/j.ijhydene.2006.08.047.

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44

Kao, A. S., H. A. Kuhn, W. A. Spitzig y O. Richmond. "Influence of Superimposed Hydrostatic Pressure on Bending Fracture and Formability of a Low Carbon Steel Containing Globular Sulfides". Journal of Engineering Materials and Technology 112, n.º 1 (1 de enero de 1990): 26–30. http://dx.doi.org/10.1115/1.2903182.

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Bend tests under superimposed hydrostatic pressure were carried out on a low carbon steel containing globular sulfide inclusions to investigate the variation of ductile fracture and forming limits due to supression of void growth. Results show that increasing pressure enhances formability, as expressed by increasing intercept and decreasing slope of the forming limit line, due to a pressure-induced transition in fracture mechanism. A continuum mechanical model based on the growth and coalescence of voids under applied pressure is proposed that explains the experimental results and predicts the fracture limit under actual metalforming conditions.

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45

Međo, Bojan, Marko Rakin, Nenad Gubeljak y Aleksandar Sedmak. "Application of Complete Gurson Model for Prediction of Ductile Fracture in Welded Steel Joints". Key Engineering Materials 399 (octubre de 2008): 13–20. http://dx.doi.org/10.4028/www.scientific.net/kem.399.13.

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Ductile fracture process includes three stages: void nucleation, their growth and coalescence. The voids nucleate due to the fracture or separation of non-metallic inclusions and secondary-phase particles from the material matrix. Micromechanical models based on the Gurson plastic flow criterion are often used for analysis of ductile fracture. They consider the material as a porous medium in which the effect of voids on the stress-strain state and plastic flow cannot be neglected. Another important property of the Gurson criterion is that the hydrostatic stress component influences the plastic flow of the material.

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46

Ayatollahi, Majid R., David John Smith y M. J. Pavier. "Effect of Constraint on the Initiation of Ductile Fracture in Shear Loading". Key Engineering Materials 261-263 (abril de 2004): 183–88. http://dx.doi.org/10.4028/www.scientific.net/kem.261-263.183.

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Research studies for mode I cracks have shown that fracture toughness or the critical value of J for fracture initiation, Jcrit is not merely a material property but depends also on the geometry and loading configurations. The geometry dependency of fracture toughness can be attributed to the effect of the crack tip constraint. In this paper, the constraint effect is studies for the initiation stage in mode II ductile crack growth. Two major mechanisms of ductile fracture: 'void growth and coalescence' and 'shear band localization and de-cohesion' are considered. A boundary layer model is simulated using the finite element method and the effect of far-filed T-stress on the relevant stress parameters near the crack tip is studied. It is shown that the initiation of the ductile crack growth in mode II is influenced significantly by T for the mechanism of void growth and coalescence and is insensitive to T for the mechanism of shear localisation and de-cohesion.

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47

Tong, W. y G. Ravichandran. "Inertial Effects on Void Growth in Porous Viscoplastic Materials". Journal of Applied Mechanics 62, n.º 3 (1 de septiembre de 1995): 633–39. http://dx.doi.org/10.1115/1.2895993.

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The present work examines the inertial effects on void growth in viscoplastic materials which have been largely neglected in analyses of dynamic crack growth and spallation phenomena using existing continuum porous material models. The dynamic void growth in porous materials is investigated by analyzing the finite deformation of an elastic/viscoplastic spherical shell under intense hydrostatic tensile loading. Under typical dynamic loading conditions, inertia is found to have a strong stabilizing effect on void growth process and consequently to delay coalescence even when the high rate-sensitivity of materials at very high strain rates is taken into account. Effects of strain hardening and thermal softening are found to be relatively small. Approximate relations are suggested to incorporate inertial effects and rate sensitivity of matrix materials into the porous viscoplastic material constitutive models for dynamic ductile fracture analyses for certain loading conditions.

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48

Vecchio, Kenneth S. "In-situ observations of microvoid coalescence: Stacking fault energy effects". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 4 (agosto de 1990): 520–21. http://dx.doi.org/10.1017/s0424820100175739.

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Although it has been well established that microvoid coalescence occurs during static or quasi-static fracture in ductile materials, the exact mechanism for microvoid formation is still unclear. It has been argued that microvoids initiate and grow from second phase particles. However this argument cannot be used to explain the existence of microvoids on the fracture surfaces of "pure" materials. An alternative mechanism for their formation in "pure" materials is that they initiate and grow along dislocation cell walls. If this premise is true; then the nature and extent of microvoid coalescence should be related to the stacking fault energy (SFE) of the material since the latter is a controlling parameter in the formation of dislocation cells. The relationship between microvoid coalescence and stacking fault energy may have some basis since absolute cell dimensions are of the same magnitude as the observed dimple sizes. The present study examines the effect of dislocation cell structures on the formation of microvoids as a function of the stacking fault energy of a given material through direct observation of the void formation and growth process within the TEM. The fundamental aspects of the work is to correlate the dislocation substructures, void initiation, growth, and coalescence to the resulting fracture surfaces.

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49

Noolu, Naren J., Nikhil M. Murdeshwar, Kevin J. Ely, John C. Lippold y William A. Baeslack. "Degradation and failure mechanisms in thermally exposed Au–Al ball bonds". Journal of Materials Research 19, n.º 5 (mayo de 2004): 1374–86. http://dx.doi.org/10.1557/jmr.2004.0184.

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During the manufacturing and the service life of Au–Al wire bonded electronic packages, the ball bonds experience elevated temperatures and hence accelerated interdiffusion reactions that promote the transformation of the Au–Al phases and the growth of creep cavities. In the current study, these service conditions were simulated by thermally exposing Au–Al ball bonds at 175 and 250 °C for up to 1000 h. The Au–Al phase transformations and the growth of cavities were characterized by scanning electron microscopy. The volume changes associated with the transformation of the intermetallic phases were theoretically calculated, and the effect of the phase transformations on the growth of cavities was studied. The as-bonded microstructure of a Au–Al ball bond typically consisted of an alloyed zone and a line of discontinuous voids (void line) between the Au bump and the bonded Al metallization. Thermal exposure resulted in the nucleation, growth, and the transformation of the Au–Al phases and the growth of cavities along the void line. Theoretical analysis showed that the phase transformations across and lateral to the ball bond result in significant volumetric shrinkage. The volumetric shrinkage results in tensile stresses and promotes the growth of creep cavities at the void line. Cavity growth is higher at the crack front due to stress concentration, which was initially at the edge of the void line. The crack propagation occurs laterally by the coalescence of sufficiently grown cavities at the void line resulting in the failure of the Au–Al ball bonds.

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50

Barrioz, P. O., J. Hure y B. Tanguy. "Effect of dislocation channeling on void growth to coalescence in FCC crystals". Materials Science and Engineering: A 749 (marzo de 2019): 255–70. http://dx.doi.org/10.1016/j.msea.2019.01.115.

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