Ductile damage modelling with locking-free regularised GTN model

2018 ◽  
Vol 113 (13) ◽  
pp. 1871-1903 ◽  
Author(s):  
Yi Zhang ◽  
Eric Lorentz ◽  
Jacques Besson
Author(s):  
Frederick Reusch ◽  
Christian Hortig ◽  
Bob Svendsen

The purpose of the current work is the application of a recent nonlocal extension (Reusch, F., Svendsen, B., and Klingbeil, D., 2003, “Local and Non-Local Gurson-Based Ductile Damage and Failure Modelling at Large Deformation,” Eur. J. Mech. A∕Solids, 22, pp. 779–792; “A Non-Local Extension of Gurson-Based Ductile Damage Modeling,” Comput. Mater. Sci., 26, pp. 219–229) of the Gurson–Needleman–Tvergaard (GTN) model (Needleman, A., and Tvergaard, V., 1984, “An Analysis of Ductile Rupture in Notched Bars,” J. Mech Phys. Solids, 32, pp. 461–490) to the simulation of ductile damage and failure processes in metal matrix composites at the microstructural level. The extended model is based on the treatment of void coalescence as a nonlocal process. In particular, we compare the predictions of the local with GTN model with those of the nonlocal extension for ductile crack initiation in ideal and real Al–SiC metal matrix microstructures. As shown by the current results for metal matrix composites and as expected, the simulation results based on the local GTN model for both the structural response and predicted crack path at the microstructural level in metal matrix composites are strongly mesh-dependent. On the other hand, those based on the current nonlocal void-coalescence modeling approach are mesh-independent. This correlates with the fact that, in contrast to the local approach, the predictions of the nonlocal approach for the crack propagation path in the real Al–SiC metal matrix composite microstructure considered here agree well with the experimentally determined path.


2010 ◽  
Vol 1 (4) ◽  
pp. 314-331 ◽  
Author(s):  
F.J.P. Reis ◽  
L. Malcher ◽  
F.M. Andrade Pires ◽  
J.M.A. César de Sá

PurposeThe purpose of this paper is to perform a numerical assessment of two recently proposed extensions of the Gurson‐Tveegard‐Needleman ductile damage constitutive model under low stress triaxiality.Design/methodology/approachOne of the most widely used ductile damage models is the so‐called Gurson‐Tveegard‐Needleman model, commonly known as GTN model. The GTN model has embedded into its damage formulation the effects of nucleation, growth and coalescence of micro‐voids. However, the GTN model does not include void distortion and inter‐void linking in the damage evolution. To overcome this limitation, some authors have proposed the introduction of different shear mechanisms based on micromechanical grounds or phenomenological assumptions. Two of these constitutive formulations are reviewed in this contribution, numerically implemented within a quasi‐static finite element framework and their results critically appraised.FindingsThrough the analysis of the evolution of internal variables, such as damage and effective plastic strain, obtained by performing a set of numerical tests using a Butterfly specimen, it is possible to conclude that the extended GTN models are in close agreement with experimental evidence.Research limitations/implicationsEven though the results obtained with the modified GTN models have shown improvements, it can also be observed that both shear mechanisms have inherent limitations in the prediction of the location of fracture onset for some specific stress states.Originality/valueFrom the results reported, it is possible to identify some shortcomings in the recently proposed extensions of the GTN model and point out the direction of further improvements.


2015 ◽  
Vol 10 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Y. Kiliclar ◽  
I. N. Vladimirov ◽  
S. Wulfinghoff ◽  
S. Reese ◽  
O. K. Demir ◽  
...  

2000 ◽  
Author(s):  
Surya Ganti ◽  
Khaled Abdel-Tawab
Keyword(s):  

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