Parameter Calibration of GTN Damage Model and Formability Analysis of 22MnB5 in Hot Forming Process

2017 ◽  
Vol 26 (11) ◽  
pp. 5155-5165 ◽  
Author(s):  
Liang Ying ◽  
Wenquan Liu ◽  
Dantong Wang ◽  
Ping Hu
2013 ◽  
Vol 779-780 ◽  
pp. 126-129
Author(s):  
Jian Jun Chen ◽  
Yu Xi Yan ◽  
Quan Sun ◽  
Hong Liang Pan

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.


2016 ◽  
Vol 693 ◽  
pp. 800-806
Author(s):  
You Dan Guo

In high-strength steel hot forming, under the heating and quenching interaction, the material is oxidized and de-carbonized in the surface layer, forming a gradual change microstructure composed of ferrite, ferrite and martensite mixture and full martensite layers from surface to interior. The experiment enunciation: Form the table to ferrite, ferrite and martensite hybrid organization, completely martensite gradual change microstructure,and make the strength and rigidity of material one by one in order lower from inside to surface, ductility one by one in order increment in 22MnB5 for hot forming;Changes depends on the hot forming process temperature and the control of reheating furnace gas content protection, when oxygen levels of 5% protective gas, can better prevent oxidation and decarburization;Boron segregation in the grain boundary, solid solution strengthening, is a major cause of strength increase in ;The gradual change microstructure in outer big elongation properties, make the structure of the peak force is relatively flat, to reduce the peak impact force of structure, keep the structure of high energy absorption capacity;With lower temperature, the material yield strength rise rapidly,when the temperature is 650 °C, the yield strength at 950 °C was more than 3 times as much.


2018 ◽  
Vol 19 (2) ◽  
pp. 202 ◽  
Author(s):  
Rasoul Safdarian

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.


2018 ◽  
Vol 188 ◽  
pp. 01024
Author(s):  
Vincenzo Iannone ◽  
Marco Barile ◽  
Leonardo Lecce

This work deals with the fabrication of an innovative hybrid thermoplastic prepreg by continuous hot forming process. The material, suitable also for Automated Fiber Placement process, is produced through a consolidation of commercial PEEK-Carbon Fiber prepreg sandwiched between two amorphous PEI films. Consolidation is performed by a purpose-designed automated prototype equipment operating on defined pressure and thermal cycles. Then preliminary tests on first trials produced were carried out. These activities have been developed in the frame of the NHYTE project, a Research and Innovation Action funded by the European Union's H2020 framework programme, under Grant Agreement No 723309 NOVOTECH acting as Coordinator presents this paper on behalf of all Partners of the project. The proof of NHYTE project concept is the manufacturing of a fastener free and high performing fuselage portion demonstrator.


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