Prediction of Burst Pressure Using a Decoupled Ductile Fracture Criterion for Tube Hydroforming of Aerospace Alloys

2011 ◽  
Author(s):  
M. Saboori ◽  
J. Gholipour ◽  
H. Champliaud ◽  
A. Gakwaya ◽  
J. Savoie ◽  
...  
Keyword(s):  
Ductile Fracture ◽  
Fracture Criterion ◽  
Tube Hydroforming ◽  
Burst Pressure ◽  
Ductile Fracture Criterion ◽  
Aerospace Alloys

Prediction of Burst Pressure in Multistage Tube Hydroforming of Aerospace Alloys

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
M. Saboori ◽  
J. Gholipour ◽  
H. Champliaud ◽  
P. Wanjara ◽  
A. Gakwaya ◽  
...  
Keyword(s):  
Fracture Criterion ◽  
Tube Hydroforming ◽  
Burst Pressure ◽  
Forming Limit ◽  
Fracture Criteria ◽  
Material Models ◽  
Aerospace Alloys ◽  
Simulation Results ◽  
Experimental Trials ◽  
Internal Pressures

Bursting, an irreversible failure in tube hydroforming (THF), results mainly from the local plastic instabilities that occur when the biaxial stresses imparted during the process exceed the forming limit strains of the material. To predict the burst pressure, Oyan's and Brozzo's decoupled ductile fracture criteria (DFC) were implemented as user material models in a dynamic nonlinear commercial 3D finite-element (FE) software, ls-dyna. THF of a round to V-shape was selected as a generic representative of an aerospace component for the FE simulations and experimental trials. To validate the simulation results, THF experiments up to bursting were carried out using Inconel 718 (IN 718) tubes with a thickness of 0.9 mm to measure the internal pressures during the process. When comparing the experimental and simulation results, the burst pressure predicated based on Oyane's decoupled damage criterion was found to agree better with the measured data for IN 718 than Brozzo's fracture criterion.

Prediction of Burst Pressure in Multi Stage Tube Hydroforming of Aerospace Alloys

2015 ◽  
Author(s):  
M. Saboori ◽  
J. Gholipour ◽  
H. Champliaud ◽  
A. Gakwaya ◽  
J. Savoie ◽  
...  
Keyword(s):  
Fracture Criterion ◽  
Tube Hydroforming ◽  
Burst Pressure ◽  
Forming Limit ◽  
Fracture Criteria ◽  
Multi Stage ◽  
Aerospace Alloys ◽  
Simulation Results ◽  
Experimental Trials ◽  
Internal Pressures

Bursting, an irreversible failure in tube hydroforming (THF), results mainly from the local plastic instabilities that occur when the biaxial stresses imparted during the process exceed the forming limit strains of the material. To predict the burst pressure, Oyane’s and Brozzo’s decoupled ductile fracture criteria were implemented as user material models in a dynamic nonlinear commercial 3D finite element (FE) software, Ls-Dyna. THF of a round to V-shape was selected as a generic representative of an aerospace component for the FE simulations and experimental trials. To validate the simulation results, THF experiments up to bursting were carried out using Inconel 718 (IN 718) tubes with a thickness of 0.9 mm to measure the internal pressures during the process. When comparing the experimental and simulation results, the burst pressure predicated based on Oyane’s decoupled damage criterion was found to agree better with the measured data for IN 718 than Brozzo’s fracture criterion.

scholarly journals Comparison of Modified Mohr–Coulomb Model and Bai–Wierzbicki Model for Constructing 3D Ductile Fracture Envelope of AA6063

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jianye Gao ◽  
Tao He ◽  
Yuanming Huo ◽  
Miao Song ◽  
Tingting Yao ◽  
...  
Keyword(s):  
Ductile Fracture ◽  
Fracture Criterion ◽  
Fracture Strain ◽  
Stress Triaxiality ◽  
Ductile Fracture Criterion ◽  
Forming Process ◽  
Tension Tests ◽  
Wide Range ◽  
Round Bar ◽  
Fracture Envelope

AbstractDuctile fracture of metal often occurs in the plastic forming process of parts. The establishment of ductile fracture criterion can effectively guide the selection of process parameters and avoid ductile fracture of parts during machining. The 3D ductile fracture envelope of AA6063-T6 was developed to predict and prevent its fracture. Smooth round bar tension tests were performed to characterize the flow stress, and a series of experiments were conducted to characterize the ductile fracture firstly, such as notched round bar tension tests, compression tests and torsion tests. These tests cover a wide range of stress triaxiality (ST) and Lode parameter (LP) to calibrate the ductile fracture criterion. Plasticity modeling was performed, and the predicted results were compared with corresponding experimental data to verify the plasticity model after these experiments. Then the relationship between ductile fracture strain and ST with LP was constructed using the modified Mohr–Coulomb (MMC) model and Bai-Wierzbicki (BW) model to develop the 3D ductile fracture envelope. Finally, two ductile damage models were proposed based on the 3D fracture envelope of AA6063. Through the comparison of the two models, it was found that BW model had better fitting effect, and the sum of squares of residual error of BW model was 0.9901. The two models had relatively large errors in predicting the fracture strain of SRB tensile test and torsion test, but both of the predicting error of both two models were within the acceptable range of 15%. In the process of finite element simulation, the evolution process of ductile fracture can be well simulated by the two models. However, BW model can predict the location of fracture more accurately than MMC model.

scholarly journals Finite Element Analysis of Bore-expanding Processes with Ductile Fracture Criterion

1998 ◽  
Vol 84 (3) ◽  
pp. 182-187 ◽  
Author(s):  
Hirohiko TAKUDA ◽  
Ken-ichiro MORI ◽  
Masashi KANESHIRO ◽  
Natsuo HATTA
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ductile Fracture ◽  
Fracture Criterion ◽  
Ductile Fracture Criterion ◽  
Element Analysis
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