Effect of Poisson’s ratio on crack tip fields and fracture behavior of metallic glasses

Tandaiya, Parag; Ramamurty, Upadrasta; Ravichandran, G.; Narasimhan, R.

doi:10.1016/j.actamat.2008.08.018

Cited by 50 publications

(40 citation statements)

References 31 publications

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“…The maximum principal stresses climb to the peak value, which is around 9 MPa, then drop to zero and stay steady ( Figure 17). As shown in Figure 17 Haimson et al (1969), Tandaiya et al (2008) and Aliha et al (2013). During the same time, the velocities gradually increase at first then vary between the peak value, 0.4 × 10 -3 m/s, and the stable value, 0.002 × 10 -3 m/s, at which the velocities flatten out (Figure 18).…”

Section: Effect Of Poisson's Ratiomentioning

confidence: 81%

Numerical analysis of the material parameter effects on the initiation of hydraulic fracture in a near wellbore region

Xing

2015

Journal of Natural Gas Science and Engineering

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Please cite this article as: Li, Q., Xing, H., Numerical analysis of the material parameter effects on the initiation of hydraulic fracture in a near wellbore region, Journal of Natural Gas Science & Engineering (2015), doi: 10.1016/j.jngse.2015 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract: Hydraulic fracturing is recognized as a key method to enhance unconventional reservoirs, but it is also quite complicated and challenging due to so many affecting factors such as the formation material parameters, fluid behaviors and geological setting/conditions. However, in unconventional reservoirs, in the near wellbore region, the rock may consist of different materials, and the stress is redistributed during drilling and fracturing process, so the preferable hydraulic fracture path is hard to predict. This paper aims to study the effects of formation material parameters, including drilling effects, on the hydraulic fracturing process in unconventional reservoirs. First, hydraulic fracturing has been simulated in nine cases with different parameters specifically permeability, porosity, Young's modulus, and Poisson's ratio. Then hydraulic fracturing has been studied by a heterogeneous model with multiple zones and layers, and complex stress condition. It is found that under a constant hydraulic pressure boundary, when the values of permeability, porosity, Young's modulus, and Poisson's ratio are higher, hydraulic fracturing initiates earlier; with a heterogeneous distribution of materials, stress concentration is formed between different materials, and the tensile stress concentrated areas become the preferable paths of hydraulic fracturing. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT

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Section: Effect Of Poisson's Ratiomentioning

confidence: 81%

Numerical analysis of the material parameter effects on the initiation of hydraulic fracture in a near wellbore region

Xing

2015

Journal of Natural Gas Science and Engineering

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“…Because ductile dendrites in BMG matrix composites can stabilize BMGs against the catastrophic fracture, producing graceful failure [11][12][13][14]. The finite-element simulation results based on the Mohr-Coulombbased constitutive model demonstrate that the extent of the plastic zone and the multiplication of shear bands ahead of a notch tip will be enhanced by a higher Poisson ratio [15]. However, the insensitivity of the Poisson ratio to the fracture toughness has been reported in some Ni-based BMGs [16,17].…”

Section: Introductionmentioning

confidence: 87%

Improvement of dynamic notch toughness for the Zr 56 Co 28 Al 16 bulk metallic glass by local pre-deformation

Zhang

Jiao

et al. 2017

Journal of Non-Crystalline Solids

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A B S T R A C TMode I dynamic three-point bending fracture tests are conducted on both as-cast and local pre-deformed Zr 56 Co 28 Al 16 bulk metallic glass specimens. Similar to quasi-static cases, the notch toughness of the pre-compressed specimens is improved compared with that of as-cast ones upon dynamic loadings, which is mainly attributed to the fact that the pre-compression can produce numerous shear bands, especially for main shear band, guiding and deflecting the cracks. In addition, the crack patterns and fractography are analyzed to evaluate the influence of local pre-existing shear bands on the dynamic fracture toughness.

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“…Their intrinsic inability to undergo finite plastic straining under tension greatly impedes MGs from wide structural usage. The underlying deformation and fracture physics, being one of the most fundamental problems of MGs, has attracted substantial research effort for the last decades (Spaepen, 1975;Argon and Salama, 1976;Ravichandran and Molinari, 2005;Schuh et al, 2007;Jiang et al, 2008a;Raghavan et al, 2009;Tandaiya et al, 2009;Xu et al, 2010;Chen et al, 2011;Jang et al, 2011;Greer et al, 2013;Tandaiya et al, 2013;Narayan et al, 2014;Narasimhan et al, 2015). Due to their special atomic structures, MGs may go through ductile failure via shear banding (Dai et al, 2005;Jiang et al, 2008b;Chen and Lin, 2010;Chen et al, 2013;Greer et al, 2013) or brittle fracture by cavitation (Jiang et al, 2008a;Murali et al, 2011a;Singh et al, 2013Singh et al, , 2014.…”

Section: Introductionmentioning

confidence: 99%

“…For pressure sensitive plastic solids, Subramanya et al (2007) performed a 3D finite element analysis of mode I crack tip fields under small-scale yielding (SSY) conditions. The crack tip for MGs was studied by Tandaiya et al(2007Tandaiya et al( , 2008, by using a continuum elastic-viscoplastic constitutive theory developed by Anand and Su (2005), and it was found that these features of plastic field, in turn, are influenced by the mechanical characteristics of MGs like Poisson's ratio and pressure sensitivity. Henann and Anand (2009) conducted finite-element simulations of fracture initiation at notch tip in a MG under mode I, plain-strain, SSY conditions, and revealed the correlations of the fracture toughness with notch-tip radius and elastic modulus.…”

Section: Introductionmentioning

confidence: 99%

“…At nanoscale, these inelastic deformation and fracture is accommodated by atomic clusters called as shear transformation zones (STZs) (Argon, 1979;Falk and Langer, 1998) or tension transformation zones (TTZs) (Jiang et al, 2008a;Huang et al, 2014a). The initiation and propagation of a shear band or a crack largely depend on the surrounding stress and deformation fields (Tandaiya et al, 2007(Tandaiya et al, , 2008Huang et al, 2014b;Wu et al, 2015). As a critical region ahead of the crack tip, plastic zone may trigger or inhibit the shear banding or cracking and therefore determine the overall deformation and failure behavior, being a bridge between the micro-deformation and the macro-failure (Ashby and Greer, 2006).…”

Section: Introductionmentioning

confidence: 99%

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Nature of crack-tip plastic zone in metallic glasses

Chen

Dai

2016

International Journal of Plasticity

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a b s t r a c tThe fracture of metallic glasses(MGs) can be induced by shear banding in a ductile mode or by cavitation in a brittle way. Plastic zone in front of a crack tip, which is greatly involved with localized shear band, cavitation and the resultant fracture morphology, is a key clue to unveil the secrets of the intrinsic ductility and fracture. However, the characteristics of plastic zone, i.e., stress and strain distributions, size and shape, have not been clearly unraveled for MGs so far. In this paper, an analytical solution of the plastic zone for mode I crack under plane strain condition is derived through J-integral based on a slip line field analysis and shape approximation, by taking pressure-sensitivity, dilatancy, and structural evolution into account. Two length scales of the plastic zone, i.e. the maximum radius R max and the radius along the crack line direction R x , are revealed to control shear flow instability and cavitation, and therefore failure modes. According to shear transformation zone (STZ) based free volume evolution dynamics, the critical values of the mode I stress intensity factor and the plastic zone size at crack initiation are obtained. The effects of Poisson's ratio, pressure sensitivity, and dilatancy on the stress/strain distributions, and the size of plastic zone are elucidated. It is found that larger Poisson's ratio and smaller dilatancy lead to higher fracture toughness and 'slender' critical plastic zone, facilitating a good ductility. The internal correlations of the fracture pattern (i.e. dimple structure) with the plastic zone are established, where the size of the fracture pattern is quantitatively characterized by the critical length of plastic zone. To be further, a shape change of the critical plastic zone from 'slender' (apt to shear plastic flow) to 'chubby' (inclined to cavitation) is revealed with increasing dilatancy or decreasing Poisson's ratio, which might shed light on the underlying mechanism of ductile-to-brittle transition in MGs.

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Effect of Poisson’s ratio on crack tip fields and fracture behavior of metallic glasses

Cited by 50 publications

References 31 publications

Numerical analysis of the material parameter effects on the initiation of hydraulic fracture in a near wellbore region

Numerical analysis of the material parameter effects on the initiation of hydraulic fracture in a near wellbore region

Improvement of dynamic notch toughness for the Zr 56 Co 28 Al 16 bulk metallic glass by local pre-deformation

Nature of crack-tip plastic zone in metallic glasses

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