scholarly journals A Consistent Relationship between the Stress and Plastic Strain Components and Its Application in Deep Drawing Process

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.

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 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.


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 ◽  
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.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1058 ◽  
Author(s):  
Miroslav Tomáš ◽  
Emil Evin ◽  
Ján Kepič ◽  
Juraj Hudák

Similitude theory helps engineers and scientists to accurately predict the behaviors of real systems through the application of scaling laws to the experimental results of a scale model related to the real system by similarity conditions. The theory was applied when studying the deep drawing process of a bathtub made from cold rolled low carbon aluminum-killed steel from the point of view of material limits. The bathtub model was created on the basis of geometric, physical, and mechanical similarity on a scale of 1:5. Thus, simulations and physical models were created. The simulation model was used to verify the combination yield locus/hardening law on the basis of comparing the thickness change. As a result, Hill 48/Krupkowski showed the minimal deviation by comparing data evaluated from numerical simulations and that measured on the physical model. Additionally, material anisotropy was modelled when virtual materials were defined from experimentally measured values of the plastic strain ratio. As an outcome, extra deep drawing quality steel with an average plastic strain ratio of rm ≥ 1.47 and an average strain hardening exponent of nm ≥ 0.23 must be used for the deep drawing of the bathtub.


2015 ◽  
Vol 651-653 ◽  
pp. 1072-1077 ◽  
Author(s):  
Yasunori Harada ◽  
Minoru Ueyama

This paper deals with the formability of pure titanium sheet in square cup deep drawing. Pure titanium has very excellent corrosion resistance. In the metal forming process, pure titanium has very good ductility in cold forming. The normal anisotropy of pure titanium is very high. Therefore, the property is suitable to the sheet metal forming, such as deep drawing process. However, the most important problem is that the occurrence of seizure becomes remarkable in severe forming operations. Many investigations on the effect of processing conditions on the seizure of titanium were carried out. In the present study, the formability of pure titanium sheet in square cup deep drawing was investigated. For the prevention, pure titanium sheets were treated by heat oxide coating. The fresh and clean titanium is not in direct contact with the die during the forming due to the existence of the oxide layer. The material was pure titanium sheets of the JIS grade 2. The initial thickness of the blank was 0.5 mm in thickness. In the deep drawing process, the sheets were employed and a flat sheet blank is formed into a square by a punch. Forming of sheet by multi-stage deep drawing was tried. Various cups were drawn by exchanging the punch and die. The die was taper without a blankholder in the subsequent stages. The effects of the intermediate annealing and tool shape on the occurrence of seizure in square cup deep drawing were also examined. The square cups were successfully drawn by heat oxide coating. The coating of titanium sheet has sufficient ability in preventing the seizure in multi-stage deep drawing operation. The results of the present study revealed that the pure titanium square cups were successfully formed by using heat oxide coating treatment.


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.


2011 ◽  
Vol 462-463 ◽  
pp. 200-206 ◽  
Author(s):  
Farzad Moayyedian ◽  
Mehran Kadkhodayan

This paper deals with two-dimensional plane stress wrinkling model of elastic/plastic annular plate. Based on energy method and nonlinearity of strain-displacement law, a bifurcation functional in polar coordinate is derived analytically. This technique leads to the critical conditions for the onset of the elastic/plastic wrinkling of the flange during the deep-drawing process. Tresca yield criterion along with deformation theory of plasticity are utilized and the material of the plate is assumed to behave perfectly plastic. Moreover, the influence of the blankholder upon wrinkling and on the number of the generated waves is quantitatively predicted by the suggested scheme. The main advantage of the proposed solution is its better agreement with the experimental and analytical results found by the other resarchers.


2010 ◽  
Vol 148-149 ◽  
pp. 769-773
Author(s):  
Yu Qing Shi

Deep-drawing is one of the most important methods to form sheet metal ,but wrinkling and fracture are the main failure modes in sheet-metal forming. Blank shape is important for deep-drawing because of an effective way to promote deep formability sheet metal .This paper presents an attempt to determine the effect of circle blank with circular diving equally small hole on edge of circle blank on the fracture and wrinkling and was investigated using 08Al sheet metal .The circular blank with small hole of diameter = was analyzed to eliminate wrinkling and fracture in deep-drawing .The aim of this study is to investigate the circular diving equally small hole on edge of circle blank on formability in the deep-drawing process and to obtain useful date from the industrial field .The experiment show that limit formability promote with punching small holes on circle blank in deep-drawing process.


Sign in / Sign up

Export Citation Format

Share Document