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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 40813 (08)
- University: Sharif University of Technology
- Department: Mechanical Engineering
- Advisor(s): Asempour, Ahmad
- Abstract:
- In this research two stage deep drawing has been analyzed by the upper bound method. During this study, the deep drawings of cylindrical parts have been analyzed. In this method, for the first stage the whole deformation region is divided into five zones including punch bottom, punch radius, between punch and die, die radius and flange. Then, the geometric equations of each zones is generated by sweeping the section curves defined on the boundary of each zone. The velocity fields are expressed in a similar manner by sweeping the boundary velocity functions. At each stage, with the change of height between punch and die, the point location is changed and movement and tension in the sheet are created. Since this movement requires energy to move, the required energy needs to be calculated. In order to calculate the energy we need both the amount of strain and stress values. Based on minimum energy principle, the movement of points should be performed in a way that the energy consumption is minimized. The speed parameters can be changed in order to satisfy this condition. The simulated annealing method has been used for obtaining speed parameters. For the second stage, the part is divided to seven to nine zones (depending on whether flange is remain or not) and geometric equations can be generated for these zones. To consider the changes in material properties, they should be stored at the end of the first stage. At the beginning of the second stage the material properties are recalled as primary material state. For evaluating this procedure, two stage deep drawing of cylindrical parts are analyzed and force-punch displacement and thickness distribution in that part have been obtained. Then the results are compared with the experiments. The results show that the predicted sheet behavior in the deep drawing process by the proposed method is well matched with the experiments. The validity of the process can be compared with FLD curves. If there need to provide some changes in whole process, these changes are performed and the process is reiterated
- Keywords:
- Simulated Annealing Method ; Deep Drawing ; Upper Bound Method ; Energy Method ; Two Stage Deep Drawing
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