Implementation of a Shear Modified GTN Damage Model and its Application in Cold Rolling

2013 ◽  
Vol 815 ◽  
pp. 758-764 ◽  
Author(s):  
Quan Sun ◽  
Yu Xi Yan ◽  
Jian Jun Chen ◽  
Xiao Xue Li ◽  
Hong Liang Pan
Keyword(s):  
Cold Rolling ◽  
Shear Test ◽  
Damage Model ◽  
Rolling Process ◽  
Gtn Model ◽  
Damage Behavior ◽  
Ductile Materials ◽  
Gtn Damage Model ◽  
Simulation Results

To characterize the degradation of material at low triaxiality, the shear modified GTN damage model proposed by Nahshon and Hutchinson (2008) was introduced in this study. The details of the numericalimplementation and validation of the model was conducted. And the shear modified parameter was determined by the comparisons of experimental and simulation results of the shear test. Then, the damage model was employed to simulate the cold rolling process, and the results showed that the shear modified GTN model can reveal the damage behavior and predict edge crackingof ductile materials in cold rolling.

Analysis for the Propagation of Edge Crack of Silicon Steel during Cold Rolling Process Based on GTN Damage Model

2012 ◽  
Vol 482-484 ◽  
pp. 487-492
Author(s):  
Yu Xi Yan ◽  
Quan Sun ◽  
Jian Jun Chen ◽  
Hong Liang Pan
Keyword(s):  
Cold Rolling ◽  
Edge Crack ◽  
Damage Model ◽  
Rolling Process ◽  
Silicon Steel ◽  
Damage Distribution ◽  
Initiation And Propagation ◽  
Gtn Damage Model ◽  
Edge Cracks ◽  
Good Agreement

Silicon steels tend to develop edge cracks during cold rolling, which need to be removed and cause rupture of the steel in the rolling mill. Hence, it is necessary to understand the formation of edge cracks. The damage distribution and the initiation and propagation of edge cracks occur around the notch tip during cold rolling process was investigated by using GTN damage model. The damage parameters f0, fcand fFare determined by tension experiments and SEM observation. The influence of various rolling parameters on damage distribution and crack length was simulated by using ABAQUS. The numerical results show that the GTN damage model is available to prediction the initiation and propagation of edge cracks during rolling process. Parametric study carried out in this present work reveals that the possible occurrence of edge cracks is higher at larger reduction, higher friction coefficient, smaller roll radius and stronger unit tension. The simulation and experimental results have a good agreement .

Prediction of Edge Crack in Cold Rolling of Silicon Steel Strip Based on an Extended Gurson–Tvergaard–Needleman Damage Model

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Quan Sun ◽  
Jianjun Chen ◽  
Hongliang Pan
Keyword(s):  
Cold Rolling ◽  
Edge Crack ◽  
Steel Strip ◽  
Damage Model ◽  
Rolling Process ◽  
Reduction Ratio ◽  
Shear Damage ◽  
Gtn Damage Model ◽  
Edge Cracking ◽  
Roller Radius

Edge cracking is commonly observed in cold rolling process. However, its failure mechanism is far from fully understanding due to the complex stresses and plastic flow conditions of steel strip under the rolling condition. In this paper, an extended Gurson–Tvergaard–Needleman (GTN) damage model coupled with Nahshon–Hutchinson shear damage mechanism was introduced to investigate the damage and fracture behavior of steel strip in cold rolling. The results show that extended GTN damage model is efficient in predicting the occurrence of edge crack in cold rolling, and the prediction is more accurate than that of the original GTN damage model. The edge cracking behavior under various cold rolling process parameters is investigated. It comes to the conclusion that edge crack extension increases with the increase of the reduction ratio, tension and the decrease of the roller radius and friction coefficient. The influence of shear damage becomes more significant in rolling condition with a larger reduction ratio, smaller roller radius, lower friction force, and tension.

On the Utilization of Shear Modified GTN Damage Model in Cold Rolling

2015 ◽  
Vol 750 ◽  
pp. 47-50
Author(s):  
Quan Sun ◽  
Da Qian Zan ◽  
Hong Liang Pan ◽  
Jian Jun Chen
Keyword(s):  
Cold Rolling ◽  
Fracture Behavior ◽  
Steel Strip ◽  
Damage Model ◽  
Damage Mechanism ◽  
Rolling Process ◽  
Complex Stress ◽  
Damage And Fracture ◽  
Rolling Experiment ◽  
Gtn Damage Model

Edge cracking is a commonly observed phenomenon in cold rolling process, but researchers appear to be far from fully understanding its failure mechanism due to the complex stress conditions of steel strip under the rolling condition. In this research, the shear modified GTN damage model coupled with Nahshon-Hutchinson shear damage mechanism was applied to investigate the damage and fracture behavior of steel strip in cold rolling. The results show that the shear modified GTN damage model is competent to predict the damage and fracture behavior of steel strip in cold rolling. By comparison to the cold rolling experiment, it presents that the prediction of edge crack occurrence of the shear modified GTN damage model is more accurate than that of the original GTN damage model.

scholarly journals Forming limit diagram prediction of 6061 aluminum by GTN damage model

2018 ◽  
Vol 19 (2) ◽  
pp. 202 ◽  
Author(s):  
Rasoul Safdarian
Keyword(s):  
Damage Model ◽  
Forming Limit Diagram ◽  
Numerical Results ◽  
Experimental Results ◽  
Correct Selection ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Gtn Model ◽  
Gtn Damage Model

Forming limit diagram (FLD) is one of the formability criteria which is a plot of major strain versus minor strain. In the present study, Gurson-Tvergaard-Needleman (GTN) model is used for FLD prediction of aluminum alloy 6061. Whereas correct selection of GTN parameters’ is effective in the accuracy of this model, anti-inference method and numerical simulation of the uniaxial tensile test is used for identification of GTN parameters. Proper parameters of GTN model is imported to the finite element analysis of Nakazima test for FLD prediction. Whereas FLD is dependent on forming history and strain path, forming limit stress diagram (FLSD) based on the GTN damage model is also used for forming limit prediction in the numerical method. Numerical results for FLD, FLSD and punch’s load-displacement are compared with experimental results. Results show that there is a good agreement between the numerical and experimental results. The main drawback of numerical results for prediction of the right-hand side of FLD which was concluded in other researchers’ studies was solved in the present study by using GTN damage model.

Study on Fracture Behavior of Steel Strip under Cold Rolling Forming Process Based on GTN Damage Model

2013 ◽  
Vol 779-780 ◽  
pp. 126-129
Author(s):  
Jian Jun Chen ◽  
Yu Xi Yan ◽  
Quan Sun ◽  
Hong Liang Pan
Keyword(s):  
Crack Propagation ◽  
Fracture Behavior ◽  
Steel Strip ◽  
Damage Model ◽  
Forming Process ◽  
Strip Steel ◽  
Initiation And Propagation ◽  
Gtn Damage Model ◽  
Edge Cracks ◽  
Simulation Results

In this paper the behavior of crack propagation of the strip steel is investigated by using the Gurson-Tvergaard-Needleman (GTN) damage model. The damage parameters used in the damage model are determined by tension experiments and SEM observation. With the aid of finite element method the influences of rolling ruduction and tension on crack propagation are systematically analyzed. The numerical results show that the GTN damage model is available to prediction the initiation and propagation of edge cracks during rolling forming process and the simulation results agrees well with the experimental results.

FEA Simulation of Clinching Process Based on GTN Damage Model

2013 ◽  
Vol 652-654 ◽  
pp. 2254-2260 ◽  
Author(s):  
Bai Jun Shi ◽  
Shu Hui Liao ◽  
Song Peng ◽  
Hang Li
Keyword(s):  
Simulation Model ◽  
Sheet Material ◽  
Damage Model ◽  
Model Parameters ◽  
Material Damage ◽  
Gtn Damage Model ◽  
Fea Simulation ◽  
Simulation Results ◽  
Clinch Joining ◽  
Joining Process

In this work, the Gurson-Tvergaard-Needleman (GTN) damage model is adopted to depict the material damage during the clinch joining process in a simulation-based theoretical model. The parameters of the GTN model which influence the void nucleation, growth and coalescence are identified. Their values of a specific material, C45E4 (ISO) steel, have been determined after carefully comparing the simulation results with the real sheet material tensile test. The established GTN damage model parameters are then imported into the simulation model to investigate the material damage during the mechanical clinch joining process. The Finite Element Analysis (FEA) simulation results show promising, because the material’s initial damage position can be located and analyzed. For a given design, the initial fracture point was predicted which is located on the inner side of the clinched joint neck of the upper sheet, which matches with the results of the experimental test very well. It can be concluded that the incorporation of GTN damage model has extend the capability of the simulation model.

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