Finite Element Analysis for Deep Drawing of Tailored Heat Treated Blanks

Author(s):  
M. Kerausch ◽  
Marion Merklein ◽  
Detlev Staud
2005 ◽  
Vol 6-8 ◽  
pp. 343-352 ◽  
Author(s):  
M. Kerausch ◽  
Marion Merklein ◽  
Detlev Staud

Aluminum alloys, due to their low density compared to steels, are an important group of materials, in particular for light weight construction of transport vehicles. However, aside from their low specific weight, drawing of car body components made from aluminum alloys is limited by an inferior formability. To enable a modern car body design, it is necessary to enhance the formability of aluminum sheet metal. One basic approach to reach this aim is to adapt the mechanical properties of the blank for the drawing process. The general idea is to soften the deformation zone relative to the force transferring zone, which results in an improved material flow and thus to larger drawing depths. In this paper the process sequence consisting of local induction heat treatment followed by deep drawing of precipitation hardenable aluminum alloy is presented. Using an induction system, it is possible to change the mechanical properties of the 6xxx aluminum blanks in a restricted area by influencing the precipitation structure. Tensile tests characterize the conversion from the stable naturally aged condition T4 to reversible solution heat treated W conditions of AA6016 as function of temperature and time. This effect leads to a reduction of flow stress, which is used to design an material property distribution adapted for the subsequent deep drawing process. A process characterization study provides detailed information concerning induction heating parameters, to improve the deep drawing of cylindrical cups, which results in a decisive increase of the limiting drawing ratio. Accompanying the experimental investigations, a finite element analysis approach is realized as a process design and optimization tool. Following the presented strategy, it is possible to enhance the forming capability of aluminum alloys. This leads to advanced manufacturing processes, which extend the field of applications for aluminum car body parts.


2021 ◽  
Vol 11 (6) ◽  
pp. 2547 ◽  
Author(s):  
Carlo Prati ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Maurizio Ventre ◽  
...  

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.


2017 ◽  
Vol 52 (4) ◽  
pp. 258-273 ◽  
Author(s):  
D Raja Satish ◽  
D Ravi Kumar ◽  
Marion Merklein

Formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied. Forming limit strains of sheets of two different thicknesses have been determined experimentally in different modes of deformation (biaxial tension, plane strain and tension–compression) by varying temperature and punch speed. A correlation has been established for plane strain intercept of the forming limit diagram (FLD0) with temperature, punch speed and thickness from the experimental results. This correlation has been used to plot the forming limit diagrams for failure prediction in the finite element analysis of warm deep drawing of cylindrical cups. The effect of strain and strain rate on material flow behavior has been incorporated using a strain rate–sensitive power hardening law in which the strain hardening exponent and strain rate sensitivity index have been experimentally determined. The predictions from simulations have been validated by warm deep drawing experiments. Large improvement in accuracy of failure prediction has been observed using the FLDs plotted based on the developed correlation when compared to the existing method of calculating FLD0 using only strain hardening coefficient and thickness. The results clearly indicate the importance of incorporating temperature and punch speed in failure prediction of Al alloys using FLDs in the warm working temperature range.


2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987456 ◽  
Author(s):  
Dyi-Cheng Chen ◽  
Li Cheng-Yu ◽  
Yu-Yu Lai

With the advancement of technology, aiming for achieving a greater lightness and smaller size of 3C products, parts processing technology not only needs to explore the basic scientific theory of materials but also needs to discuss the process of deep drawing numerical and the plastic deformation. This study is based on the square shape of the deep drawing numerical simulation, and aluminum alloy plastic flow stress was input into the finite element method for simulation of plastic deformation in the aluminum alloy friction, mold clamping force, and frequency, as well as amplitude in the influence of forming mechanism and the drawing ratio of aluminum alloy. Finite element analysis software has the function of grid automatic rebuild, which can rebuild the broken grid in the analysis into a complete grid shape, which can avoid the divergence caused by numerical calculation in the analysis process. The greater the obtained error value, the best plastic parameters can be found.


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