Modelling of dynamic ductile fracture and application to the simulation of plate impact tests on tantalum

Czarnota, Christophe; Jacques, Nicolas; Mercier, Sébastien; Molinari, A.

doi:10.1016/j.jmps.2007.07.017

Cited by 113 publications

(64 citation statements)

References 49 publications

(51 reference statements)

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“…Since the evolution of porosity and stress are not coupled, this model is able to describe only the early stage of damage. The work of Molinari and Wright (2005) has been extended by Wright and Ramesh (2008) and Czarnota et al (2008) in order to consider the nucleation and void growth up to finite porosity and to predict the macroscopic response of the material. The model proposed by Czarnota et al (2008) has been implemented in a finite element software.…”

Section: Introductionmentioning

confidence: 99%

A micromechanical constitutive model for dynamic damage and fracture of ductile materials

et al. 2010

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WOSInternational audienceThis paper proposes a detailed theoretical analysis of the development of dynamic damage in plate impact experiments for the case of high-purity tantalum. Our micro-mechanical model of damage is based on physical mechanisms (void nucleation and growth). The model is aimed to be general enough to be applied to a variety of ductile materials subjected to high tensile pressure loading. In this respect, the work of Czarnota et al. (J Mech Phys Solids 56:1624–1650, 2008) has been extended by introducing the concept of nucleation law and by entering a nonlinear formulation of the elastic response based on the Mie-Grüneisen equation of state. This later aspect allows us to consider high impact velocities. All model parameters are directly assessed by experimental measurements to the exception of the nucleation law which is characterized by the way of an inverse identification method using three free-surface velocity profiles (at low, intermediate and high impact velocities). It is shown that the nucleation law can be consistently determined in the range of operating pressures. The nucleation law being identified, the development of internal damage happens to be a natural outcome of the modelling. The model is applied to predict damage development and free-surface velocity profiles for various test conditions. The variety and the quality of results support the physical basis (in particular micro-inertia effects) upon which the proposed model of dynamic damage is based

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Section: Introductionmentioning

confidence: 99%

A micromechanical constitutive model for dynamic damage and fracture of ductile materials

et al. 2010

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“…Overall, this simple step, together with added viscosity s r , reduced the degree of sensitivity of numerical results due to computational cell size. Although not included in this model, inertial effects of pore growth 44 are also believed to be relevant for high density materials such as tantalum and also are expected to introduce additional regularization effects through the additional time rate sensitivity of pore growth.…”

Section: à4mentioning

confidence: 99%

Response and representation of ductile damage under varying shock loading conditions in tantalum

Bronkhorst

Gray

Addessio

et al. 2016

Journal of Applied Physics

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The response of polycrystalline metals, which possess adequate mechanisms for plastic deformation under extreme loading conditions, is often accompanied by the formation of pores within the structure of the material. This large deformation process is broadly identified as progressive with nucleation, growth, coalescence, and failure the physical path taken over very short periods of time. These are well known to be complex processes strongly influenced by microstructure, loading path, and the loading profile, which remains a significant challenge to represent and predict numerically. In the current study, the influence of loading path on the damage evolution in high-purity tantalum is presented. Tantalum samples were shock loaded to three different peak shock stresses using both symmetric impact, and two different composite flyer plate configurations such that upon unloading the three samples displayed nearly identical "pull-back" signals as measured via rear-surface velocimetry. While the "pull-back" signals observed were found to be similar in magnitude, the sample loaded to the highest peak stress nucleated a connected field of ductile fracture which resulted in complete separation, while the two lower peak stresses resulted in incipient damage. The damage evolution in the "soft" recovered tantalum samples was quantified using optical metallography, electron-back-scatter diffraction, and tomography. These experiments are examined numerically through the use of a model for shock-induced porosity evolution during damage. The model is shown to describe the response of the tantalum reasonably well under strongly loaded conditions but less well in the nucleation dominated regime. Numerical results are also presented as a function of computational mesh density and discussed in the context of improved representation of the influence of material structure upon macro-scale models of ductile damage. V C 2016 AIP Publishing LLC.

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“…39,[54][55][56][57][58][59][60][61][62] Moreover, a few modeling papers have suggested that the porosity achieved at the peak tensile stress is typically low (<1%), and the void coalescence is achieved long after the peak tensile stress. [63][64][65] Thus, it was proposed that the void coalescence behavior has no perceivable influence on the pull-back velocity and spall strength. [63][64][65] In the previous research, the influences for the strain hardening ability and the yield strength under quasi-static uniaxial stress conditions on the spall strength have been experimentally and numerically investigated.…”

Section: Effect Of the Microstructure On The Shock And Spall Behaviormentioning

confidence: 99%

“…[63][64][65] In the previous research, the influences for the strain hardening ability and the yield strength under quasi-static uniaxial stress conditions on the spall strength have been experimentally and numerically investigated. 63,[65][66][67] Thus, the strain hardening ability and the yield strength under quasi-static uniaxial stress conditions, the HEL, and the spall strength have been plotted in Fig. 11 for the two microstructures.…”

Section: Effect Of the Microstructure On The Shock And Spall Behaviormentioning

confidence: 99%

Shock and spall behaviors of a high specific strength steel: Effects of impact stress and microstructure

Wang

Zhang

Yang

et al. 2017

Journal of Applied Physics

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A series of plate-impact experiments were conducted to investigate the influences of impact stress and microstructure on the shock and spall behaviors of a high specific strength steel (HSSS). The HSSS shows a strong positive strain rate sensitivity on the yield strength. With increasing impact stress up to about 6 GPa, the spall strength is found to decrease significantly and then levels off with further increasing impact stress. This trend is proposed to be attributed to the accumulation damage within the target as the initial shock-induced compression wave propagates through the target. The microcracks are clearly observed to nucleate from the interfaces between γ-austenite and B2 phase and propagate along the interfaces or cut through the B2 phase in the HSSS during the spalling process. The Hugoniot elastic limit and the spall strength were found to be highly dependent on the microstructure. The spall strength was found to be higher when the density of the void nucleation sites is lower, indicating that the spall strength should be a microstructure parameter of the HSSS under impact tensile conditions depending on the density of phase interfaces. It was also found that there is a tradeoff between the specific yield strength and the spall strength for this HSSS; thus, the current findings should provide insights for achieving an optimal combination of both mechanical properties for impact-resistant applications by tailoring the microstructure.

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Modelling of dynamic ductile fracture and application to the simulation of plate impact tests on tantalum

Cited by 113 publications

References 49 publications

A micromechanical constitutive model for dynamic damage and fracture of ductile materials

A micromechanical constitutive model for dynamic damage and fracture of ductile materials

Response and representation of ductile damage under varying shock loading conditions in tantalum

Shock and spall behaviors of a high specific strength steel: Effects of impact stress and microstructure

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