Finite Element Analysis of Stamping Die Design ith Advanced High Strength Steel Sheets
Date Issued
2009
Date
2009
Author(s)
Chiang, Tzu-Hsin
Abstract
In order to mitigate the greenhouse effect and promotion of fuel-efficient, how to reduce the weight of vehicle become the new goal for the automotive manufactures. It leads to the fast development and application of advanced high strength steels (AHSS). However, due to the increasing strength, the use of advanced high strength steel has encountered the forming problem just like crack, wrinkle, springback and distortion in the sheet metal forming process. It will consume the cost and times in the die development process. The V-bending, U-bending, and U-hat bending tests of 270 steel, DP590 and DP780 high strength steels were performed to examine the effects of punch speeds. A servo press was a employed to conduct the bending tests with various punch speeds to investigate the effect of stamping velocity on the springback. Significant springback was found after bending tests, while the stamping velocity has little effect on the occurrence of springback. The finite element simulations were then performed to examine the die design for structural parts front side which is tailored blank by DP590 and DP780. The multi-forming (bending and re-striking) operations were proposed to produce since the side-wall curl resulted from a draw operation being difficult to be suppressed. The die compensation approach was employed to adjust the amount of springback at each operation systematically to make the dimension of the parts conforming to the design specifications. Stamping die sets were then manufactured according to the finite element analysis. After several tryouts, stable stamping processes of producing front side were established. The accurate dimensions of the production parts validate both the finite element analysis. Tailored blanks are increasingly used in the automotive industry. A combination of material and position of welding line are discussed. Investigating springback simulation of tailored blanks is the purpose of this study. The results of this study can be reference resources for related academic research and can also be used to develop related products for industry production.
Subjects
advanced high strength steel (AHSS)
stamping
springback
die design
CAE
servo press
tailored blank
Type
thesis