New Approach for Wrinkle Prediction in Deep Drawing Process

2015 ◽  
Vol 639 ◽  
pp. 459-466
Author(s):  
Fei Han ◽  
Ranko Radonjic

Due to the extensive use of thin sheet metals to reduce weight of car bodies, wrinkling is becoming a more common and one of the most undesirable defects in sheet metal forming processes. Recent experiments at the Institute for Metal Forming Technology (IFU), University of Stuttgart, indicated that the buckling test using modified specimens can enhance accuracy for the predication of wrinkling [1]. In this paper a new method to predict the onset of the wrinkling will be introduced, and results of this test will be compared with real deep drawing parts. The wrinkle heights will be considered an evaluated regarding to results obtained by an optical measurement system.

2011 ◽  
Vol 291-294 ◽  
pp. 556-560 ◽  
Author(s):  
Salman Norouzi ◽  
Amir Reza Yaghoubi ◽  
Mohammad Bakhshi-Jooybari ◽  
Abdolhamid Gorji

Since conical parts have wide applications in the industry and forming these parts is one of the most complex and difficult fields in sheet metal forming processes, the study on different methods in forming these parts can be useful. Hydroforming and conventional multistage deep drawing are two deep drawing processes which have been used to form conical parts. Hydroforming deep drawing is one of the special deep drawing processes which have been introduced in order to overcome some inherent problems in the conventional deep drawing with rigid tools. In the present work, an experimental program has been carried out to compare the drawing load variation and maximum drawing load in forming pure copper conical-cylindrical cups with the thickness of 2.5 mm by hydroforming and conventional multistage deep drawing processes. The results of the study demonstrate that drawing load variation is more uniform in the forming of conical parts by hydroforming deep drawing process. The maximum drawing load for drawing copper blank occurs at a higher amount in hydroforming process.


2020 ◽  
Vol 977 ◽  
pp. 139-147
Author(s):  
Jaber Abu Qudeiri ◽  
Aiman Ziout ◽  
Muneir Alsayyed ◽  
Ammar Alzarooni ◽  
Faris Safieh ◽  
...  

Deep drawing process is one of the important processes in sheet metal forming. One of the challenge that faces the deep drawing process is selecting the optimal values of process parameters for the deep drawing process. In order to find the optimum values of these parameters, it is necessary to study their influence on the deformation behaviour of the sheet metal. This paper develops a simulation model for deep drawing process based on Simufact sheet metal forming module to study the effect process parameters on the deep-drawing characteristics. The study also obtained the distribution of strain on the drawn product. Three process parameters are considered in this study namely, punch radius, die radius and clearance, the effect of these process parameter on the required force as well as on the quality of the product are investigated.


2018 ◽  
Vol 5 (2) ◽  
pp. 4353-4358 ◽  
Author(s):  
Radha Krishna Lal ◽  
Vikas Kumar Choubey ◽  
J.P. Dwivedi ◽  
Shravan Kumar

Author(s):  
Dietrich Bauer ◽  
Regine Krebs

Abstract For a deep drawing process some important controllable variables (factors) upon the maximum drawing force are analyzed to find a setting adjustment for these process factors that provides a very low force for the metal forming process. For this investigation an orthogonal array L18 with three-fold replication is used. To find the optimum of the process, the experimental results are analyzed in accordance with the robust-design-method according to Taguchi (Liesegang et. al., 1990). For this purpose, so-called Signal-to-Noise-ratios are calculated. The analysis of variance for this S/N-ratios leads to a mathematical model for the deep drawing process. This model allows to find the pressumed optimal settings of the investigated factors. In the following, a confirmation experiment is carried out by using these optimal settings. The maximum drawing force of the confirmation experiment does not correspond with the confidence interval, which was calculated by analysis of variance techniques. So the predicted optimum of the process does not lead to a metal forming process with very low deep drawing force. The comparison with a full factorial plan shows that there are interactions between the investigated factors. These interactions could not be discovered by the used orthogonal array. Thus the established mathematical model does not describe the relation between the factors and deep drawing force in accordance with the practical deep drawing conditions.


2019 ◽  
Vol 153 ◽  
pp. 110-126
Author(s):  
Vamsi Krishna Balla ◽  
Laurens Coox ◽  
Elke Deckers ◽  
Francesco Greco ◽  
Bert Pluymers ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yong Zhang ◽  
Qing Zhang ◽  
Xianrong Qin ◽  
Yuantao Sun

As von Mises yield criterion and associated flow rule (AFR) are widely applied in metal forming field, a semitotal deformation consistent relationship between the stress and plastic strain components and the rule of dimensional changes of metal forming processes in a plane-stress state are obtained on the basis of them in this paper. The deduced consistent relationship may be easily used in forming interval of the workpiece. And the rule of dimensional changes can be understood through three plastic strain incremental circles on which the critical points can be easily determined on the same basis. Analysis of stress and plastic strain evolution of aluminum warm deep drawing process is conducted, and the advantage of nonisothermal warm forming process is revealed, indicating that this method has the potential in practical large deformation applications.


2019 ◽  
Vol 290 ◽  
pp. 03012
Author(s):  
Valentin Oleksik ◽  
Radu Breaz ◽  
Gabriel Racz ◽  
Paul Dan Brindasu ◽  
Octavian Bologa

The present paper analyse the main characteristics of the numerical simulation by finite element method of the deep-drawing processes. Also the authors’ highlights the mathematical apparatus and the calculus method used for numerical simulations of metal forming processes in many of the current simulation software. The authors present the capabilities of the inverse analysis, direct analysis, implicit analysis (for springback simulation) and the optimisation analysis applied to explicit formulations.


Author(s):  
Puneet Tandon ◽  
Om Namah Sharma

Incremental sheet metal forming is an evolving process, which is suitable for the production of limited quantities of sheet metal components. The main advantages of this process over conventional forming processes are reduced setup cost and manufacturing lead time, as it eliminates the need of special purpose dies, improves formability, reduces forming forces, and provides process flexibility. The objective of this work is to investigate a new hybrid-forming process, which intends to combine incremental sheet metal forming with deep drawing process and has been named as “incremental stretch drawing.” A number of setups and fixtures were developed to carry out experiments to achieve incremental stretch drawing and understand the mechanism of the process. This process addresses some of the challenges of incremental sheet metal forming, that is, limited formability in terms of forming depth, especially at steeper wall angles and subsequent thinning of sheet. It is observed that the proposed process is able to reduce thinning as much as about 300%, considering same forming depth for incremental sheet metal forming and incremental stretch drawing processes. Improvement in formability, in terms of forming depths, also has been observed to be near about 100% in particular cases.


2020 ◽  
Author(s):  
Araveeti C S Reddy

we address herein various hardening models and their suitability in computational modelling of deepdrawing process wherein magnesium alloy AZ31 as blank material. insight on all basic and advanced hardeningmodels. The basic models as well as advanced models were illustrated in usefulness of them in metal forming. Itis purely depends on the researcher to select the appropriate hardening model for extracting the real computationalbehavior resembling the true hardening property.


Author(s):  
W. J. Dan ◽  
W. G. Zhang ◽  
S. H. Li

Loading path is one of key factors that influence the formability of sheet metal forming processes. In this study, the effect of several kinds of loading paths on the thickness distribution of TRIP steel is investigated in a deep drawing process based on a constitutive model accompanying the strain-induced martensite transformation. A kinetic model of transformation, that describes the relationship between the thickness distribution of a deep drawing process and the martensite transformation, is used to calculate the martensite volume fraction. The influences of loading path on the martensite transformation are also evaluated through the change in the stress-strain state, the forming temperature, the transformation driving force, the nucleation site probability and the shear-band intersection controlled by the stress-strain state and forming temperature at the minimum thickness location in the formed part.


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