Application of an extended void growth model with strain hardening and void shape evolution to ductile fracture under axisymmetric tension

Ragab, Ahmed

doi:10.1016/s0013-7944(03)00216-9

Cited by 64 publications

(39 citation statements)

References 44 publications

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“…For the purpose of coalescence modeling, the shape evolution of an axisymmetric void can be readily incorporated into the GTN model using the semi-empirical equations of Ragab (2004b). The influence of the void shape is not considered in the GTN yield criterion as the porosity is defined based on the volume fraction of voids in the material.…”

Section: Evolution Of Void Shape and Unit Cellmentioning

confidence: 99%

“…While the influence of void volume fraction on material softening is considered, knowledge of the void geometry is critical for accurate coalescence modeling. The Ragab (2004b) equations enable us to account for the influence of void shape on coalescence while maintaining the relatively simple GTN model. According to Ragab (2004b), the void aspect ratio is expressed as λ 1 = R y /R x as shown in Fig.…”

Section: Evolution Of Void Shape and Unit Cellmentioning

confidence: 99%

“…The void shape evolution rules in Eq. 5a are valid for a relatively large range of triaxiality from 1 3 ≤ σ hyd σ ≤ 2 Ragab (2004b). Assuming the matrix material of the unit cell is incompressible, the evolution equation of Ragab (2004a) for the unit cell aspect ratio, λ 2 = L y L x , as shown in Fig.…”

Section: Evolution Of Void Shape and Unit Cellmentioning

confidence: 99%

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Damage-based finite-element modeling of tube hydroforming

et al. 2009

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Numerical simulations of straight tube hydroforming of a dual phase (DP600) advanced high strength steel were performed using a variant of the Gurson-Tvergaard-Needleman (GTN) constitutive model to account for the influence of void shape and shear on coalescence. The effect of axial-feed (end-feed) on damage development and formability is investigated for end-feed loads of zero and 133 kN. A parametric study was conducted to determine an appropriate void nucleation stress and strain and the numerical values compared with the experimental data. The calibrated GTN damage model gives good agreement with the experimentally determined burst pressure, formability and failure location with the best performance occurring for the high end-feed load.

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Section: Evolution Of Void Shape and Unit Cellmentioning

confidence: 99%

Section: Evolution Of Void Shape and Unit Cellmentioning

confidence: 99%

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Damage-based finite-element modeling of tube hydroforming

et al. 2009

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“…The strain hardening of the matrix also could reduce the prediction of these types of models. 33) Meanwhile, there were several reports demonstrating that the evolution of R was in fair agreement with two models in case of calculating with a limited number of the relatively large voids which were only concerned with growth [8][9][10]13,18) and replacing the initial value of α by a specific constant depending on a material and T state allowed them to be more valid. 9,18) These two items seem to be valuable for making the prediction better.…”

Section: )mentioning

confidence: 90%

In Situ Observation of Void Nucleation and Growth in a Steel using X-ray Tomography

et al. 2015

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“…Due to its inherent upperbound formulation, the Gurson model is rather rigid and tends to overestimate the material behaviour. Calibration parameters were soon introduced into the yield criterion by Tvergaard (1981) and later by Faleskog (1998) and Ragab (2004) to shrink and adjust the yield surface to better reflect the material behaviour obtained from finite-element simulations of voided unit cells.…”

Section: Introductionmentioning

confidence: 99%

On Using a Dual Bound Approach to Characterize the Yield Behaviour of Porous Ductile Materials Containing Void Clusters

2011

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Two constitutive models for porous ductile materials are employed together to predict the yield behaviour ductile of materials containing void clusters. In this dual bound approach, the upper and lower bound constitutive models of Gurson (1977) and Sun and Wang (1989) are each evaluated in order to obtain upper and lower estimates for the material behaviour. By combining these two solutions, a predictive band can be created to capture the experimental variation in the yielding behaviour. Although these constitutive models have been derived with the assumption of a periodic void distribution, real materials contain void clusters that can significantly alter the onset of yielding and fracture. Therefore it is of great interest to determine if using dual constitutive models can produce an acceptable first-order approximation of the yielding behaviour in these materials. In the present work, the upper and lower bound yield loci are superimposed over numerical data available in the literature for the yielding of materials containing void clusters. It is shown that the dual bound approach is able to capture the material behaviour over a wide range of practically encountered stress triaxialities.

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Application of an extended void growth model with strain hardening and void shape evolution to ductile fracture under axisymmetric tension

Cited by 64 publications

References 44 publications

Damage-based finite-element modeling of tube hydroforming

Damage-based finite-element modeling of tube hydroforming

In Situ Observation of Void Nucleation and Growth in a Steel using X-ray Tomography

On Using a Dual Bound Approach to Characterize the Yield Behaviour of Porous Ductile Materials Containing Void Clusters

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