Simulation of Semi-Active the Blank Holder Force Control to Prevent Wrinkling and Cracking in Deep Drawing Process

Abstract

This paper presents simulation of drawing force and thickness deformation in deep drawing which employs semi-active blank holder force system, to solve the problem of cracking and wrinkling. The method of slab with feed back control failure criteria, was employed to make the modeling system and the semi-active blank holder to prevent wrinkling and cracking in forming low carbon steel sheet, without lubrication (μ=0.4). In this study, the mechanical properties of the material were chosen since that they equivalent to those of low carbon steel with its thickness of 0.2 mm, k = 572 N/mm2, UTS = 391 N/mm2, yield stress = 309 N/mm2 and n = 0.2. The diameter and the depth of the cylindrical cup-shaped product were 40 mm and 10 mm, respectively. Results from simulation have shown that the semi-active blank holder system can control very responsive against changing of deformation condition. The optimum of initial blank holder force is approximately 3000 N up to 4000 N. In the early stages (initial stroke), blank holder force system could be responsive to prevent cracking, and at the end of the punch stroke, it is very effective to prevent wrinkling. Simulation of semi-active blank holder force control system is excellent in model formation to prevent cracking and wrinkling.

Development of Porous Material and Hybrid Porous Ti6Al4V Dental Implants using Metal Injection Molding (MIM)

“…A narrow BHG may lead to product cracking Figure 2: Possible fixed blank holder gap options [11] There is no single equation to calculate the blank holder gap, understanding several factors and conducting empirical testing will help in determining the appropriate gap for a successful deep drawing process. Therefore, a combination of theoretical considerations, empirical testing, and experience is necessary to determine the appropriate blank holder gap for a successful deep drawing process.…”

“…Figure 1: Forming limit diagram [11], [28] The forming strain limit (major and minor strain ratio) in the flange area is used as a boundary condition for the minimum and maximum blank holder gap, which prevents wrinkling and cracking. The major forming strain which is expressed as radial strain (1= r) in the product flange region can be calculated using the following equation [28]:…”

“…The material is used the general value for steel is 2. Then Equation ( 9) can be obtained as [11], [28]:…”

“…The semi-active control refers to the ability to dynamically adjust the blank holder force in real-time during the forming process [11], and this adjustment can be based on factors such as material properties, die geometry, or sensor feedback. By continuously monitoring and adapting the blank holder force, it can ensure that the material flows smoothly into the die cavity without any issues.…”

Analytical Study and FEM Simulation of the Maximum Varying Blank Holder Force to Prevent Cracking on Cylindrical Cup Deep Drawing

“…Under the condition of plain strains, by using the criterion of Tresca and the definition of equivalent stress [10], the relationship of radial and tangential stress can be obtained relations as. The equivalent strain can be derived from or (5) In order to simplify calculation of the mean flow stress on flange, the strain will be divided into two sections, at point 1 and point 2.…”