• Transactions of Materials Processing
• /
• v.3 no.1
• /
• pp.51-62
• /
• 1994

Cup drawing test and U-bending test were performed to evaluate the friction characteristics of sheet materials for the different deformation modes involved in stamping process. The coefficient of friction calculated from the each test was compared to that obtained from the draw bead friction test. It was clarified that the cup drawing test could be simply used for evaluating the friction characteristic of sheet material in deep drawing process with high contacting pressure. However the U-bending test is suitable to evaluate the frictional characteristic of sheet material in bending process with low contacting pressure.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.266-269
• /
• 2003

This paper is concerned with a forming analysis of front side members and the application of the forming effect in crash analysis of auto-body. Drawbead restraining forces are calculated with ABAQUS/Strandard in order to identify the boundary condition in forming process. Forming analysis with equivalent drawbead is carried out with LS-DYNA3D. In order to demonstrate the validity of the forming analysis, quantitative comparison of the thickness variation between the real product and the numerical simulation result is carried out. Forming histories obtained from the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.2 no.1
• /
• pp.96-105
• /
• 1994

Cup drawing tests were performed to evaluate the friction characteristics of sheet metals. The linear relationship between drawing force and blank holding force obtained from the cup drawing test was used to calculate the coefficient of friction of the sheet metal. The friction coefficient was compared to that from conventional draw bead friction test. It was clarified that the cup drawing test can be used as a simple and convenient method for evaluating the friction characteristic of the sheet metal and also lubricity of the lubricant used.

• Transactions of Materials Processing
• /
• v.12 no.4
• /
• pp.320-327
• /
• 2003

This paper is concerned with forming analysis of Front Side Members and effects of the forming analysis on crash analysis of an auto-body. For efficient forming analysis, equivalent draw-bead restraining forces are calculated with ABAQUS/Standard and then used as the boundary condition in forming simulation. In order to demonstrate the validity of the forming analysis, the thickness variation in the numerical simulation result is compared quantitatively with the one in the real product. Forming histories obtained kom the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness. Crashworthiness such as the load-carrying capacity, crash mode and the energy absorption is evaluated and investigated for the identification of forming effects.

• Journal of the Korean Society of Industry Convergence
• /
• v.10 no.1
• /
• pp.5-14
• /
• 2007

It is necessary for development of drawing product with press to have suitable material selection & all process design and the problem during press process has been cleared from judgement of experience & trial and error. Recently we can estimate press process result from computer aided design & FEM. But we can get more reliable result when we can put more precise process variants during FEM. In case of using a drawbead that is used for the material inflow, it is considered for us to put material property, other analysis condition & friction figure when material is passing through the drawbead for better FEM. From our study, we have drawn an analogy bead connection depth, friction figure & drawing and restraining load according to kinds of lubrication from experiment & FEM for the drawbead. We applied above result to the drawing experiment & FEM and confirmed the validity. We could notice the relation between friction figure & drawing load and the friction figure variation according to kinds of lubrication. It is expected to draw more precise analogy that can be used for real process due to more precise process variants application to FEM.