Ductile damage modelling with locking-free regularised GTN model

2018 ◽  
Vol 113 (13) ◽  
pp. 1871-1903 ◽  
Author(s):  
Yi Zhang ◽  
Eric Lorentz ◽  
Jacques Besson
Keyword(s):  
Ductile Damage ◽  
Gtn Model ◽  
Damage Modelling

Nonlocal Modeling and Simulation of Ductile Damage and Failure in Metal Matrix Composites

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Frederick Reusch ◽  
Christian Hortig ◽  
Bob Svendsen
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Propagation Path ◽  
Ductile Damage ◽  
Void Coalescence ◽  
Extended Model ◽  
Matrix Composites ◽  
Gtn Model ◽  
Damage And Failure ◽  
Non Local

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.

A comparison of shear mechanisms for the prediction of ductile failure under low stress triaxiality

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
Keyword(s):  
Stress Triaxiality ◽  
Ductile Failure ◽  
Ductile Damage ◽  
Internal Variables ◽  
Content Type ◽  
Gtn Model ◽  
Damage Models ◽  
Numerical Assessment ◽  
Damage Constitutive Model ◽  
Stress States

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.

Finite element analysis of combined forming processes by means of rate dependent ductile damage modelling

2015 ◽  
Vol 10 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Y. Kiliclar ◽  
I. N. Vladimirov ◽  
S. Wulfinghoff ◽  
S. Reese ◽  
O. K. Demir ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ductile Damage ◽  
Element Analysis ◽  
Rate Dependent ◽  
Damage Modelling

Modeling cleavage and ductile damage in welded joints

2000 ◽  
Author(s):  
Surya Ganti ◽  
Khaled Abdel-Tawab
Keyword(s):  
Welded Joints ◽  
Ductile Damage
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