The Effects of Nonproportional Biaxial Loading Paths on Ductile Fracture Initiation: A Void Growth Analysis

2020 ◽  
Vol 9 (5) ◽  
pp. 20190215
Author(s):  
Zhaoyu Jin ◽  
Xin Wang ◽  
Zheng Liu ◽  
Xu Chen
Keyword(s):  
Ductile Fracture ◽  
Void Growth ◽  
Growth Analysis ◽  
Biaxial Loading ◽  
Fracture Initiation ◽  
Loading Paths ◽  
Ductile Fracture Initiation

The Effects of Non-Proportional Biaxial Loading Paths on Ductile Fracture Initiation: A Void Growth Analysis

2019 ◽  
Author(s):  
Zhaoyu Jin ◽  
Xin Wang
Keyword(s):  
Ductile Fracture ◽  
Void Growth ◽  
Biaxial Loading ◽  
Crack Tip ◽  
Fracture Initiation ◽  
Initiation Toughness ◽  
Proportional Loading ◽  
Loading Paths ◽  
Ductile Fracture Initiation ◽  
Crack Tip Blunting

Abstract The effects of non-proportional biaxial loading paths on ductile fracture initiation toughness are studied in this paper. To this end, the growth of a cylindrical void (hole) located in front of a mode I plane strain crack has been studied using large deformation finite element analysis (FEA). A specific microstructural feature of a steel alloy was thoroughly studied by having a single void positioned at a fixed distance from the crack tip and void that was equal to 10 times the diameter of the void. In particular, the non-proportional biaxial loading path effects on the crack tip blunting, void-growth, ligament reduction and near-tip stress fields are investigated computationally. Under small-scale yielding conditions, one proportional loading and two non-proportional loading paths are applied to the modified boundary layer (MBL) model. It is observed that the non-proportional load paths have a marked effect on the void growth, crack tip blunting and their interaction. By applying the criteria for the coalescence of the crack tip and void, the ductile fracture initiation toughness is estimated. It is shown that the ductile fracture toughness is dependent on loading paths, and the T-stress ratios. Results from this study are of relevance to ductile fracture assessment of components or pressure vessels that operate under non-proportional biaxial loading conditions.

Experimental and Numerical Study of Ductile Fracture Initiation in Aluminum 6061-T6

2015 ◽  
Author(s):  
W. Rekik ◽  
O. Ancelet ◽  
C. Gardin
Keyword(s):  
Numerical Simulation ◽  
Ductile Fracture ◽  
Void Growth ◽  
Numerical Study ◽  
Micromechanical Model ◽  
Stress Triaxiality ◽  
Fracture Initiation ◽  
Compact Tension ◽  
Growth Ratio ◽  
Ductile Fracture Initiation

This work deals with the characterization of ductile damage in Aluminum 6061-T6 alloy. In this paper we discuss the stress triaxiality effect on the initiation and the evolution of damage through a sequence of tensile tests conducted on round specimens with different rate of trixialities and tearing tests on precracked Compact Tension specimens. Scattering of ductility and toughness values was highlighted between the three characteristic directions studied in this topic. Based on the experimental results, numerical simulation has been performed in order to analyze and predict ductile fracture initiation of this aluminum alloy by simulating void growth according to the Rice-Tracey micromechanical model. The numerical simulation was conducted in two steps: first the critical void growth ratio (R / R0)c was evaluated for tensile cylindrical specimens with different degrees of triaxiality and then used to analyze crack growth initiation on Compact Tension specimen. Due to the Al-6061-T6 highly sensitivity to triaxiality, a necessary adaptation of the Rice-Tracey model’s coefficient was made.

scholarly journals Prediction of Ductile Fracture in Metal Blanking

1999 ◽  
Vol 122 (3) ◽  
pp. 476-483 ◽  
Author(s):  
A. M. Goijaerts ◽  
L. E. Govaert ◽  
F. P. T. Baaijens
Keyword(s):  
Finite Element ◽  
Tensile Test ◽  
Ductile Fracture ◽  
Experimental Error ◽  
Fracture Initiation ◽  
Fracture Model ◽  
Ductile Fracture Model ◽  
Blanking Process ◽  
Ductile Fracture Initiation

This study is focused on the description of ductile fracture initiation, which is needed to predict product shapes in the blanking process. Two approaches are elaborated using a local ductile fracture model. According to literature, characterization of such a model should take place under loading conditions, comparable to the application. Therefore, the first approach incorporates the characterization of a ductile fracture model in a blanking experiment. The second approach is more favorable for industry. In this approach a tensile test is used to characterize the fracture model, instead of a complex and elaborate blanking experiment. Finite element simulations and blanking experiments are performed for five different clearances to validate both approaches. In conclusion it can be stated that for the investigated material, the first approach gives very good results within the experimental error. The second approach, the more favorable one for industry, yields results within 6 percent of the experiments over a wide, industrial range of clearances, when a newly proposed criterion is used. [S1087-1357(00)02202-4]

scholarly journals A Micromechanically-motivated Phenomenological Model for Predicting Ductile Fracture Initiation

2017 ◽  
Vol 207 ◽  
pp. 2054-2059 ◽  
Author(s):  
Lei Mu ◽  
Yong Zang ◽  
Xiao Long Li ◽  
Pedro Malaquias Araujo Stemler
Keyword(s):  
Ductile Fracture ◽  
Phenomenological Model ◽  
Fracture Initiation ◽  
Ductile Fracture Initiation
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