0
TECHNICAL PAPERS

Stress-Based Springback Reduction of a Channel Shaped Auto-Body Part With High-Strength Steel Using Response Surface Methodology

[+] Author and Article Information
Jung-Han Song

School of Mechanical, Aerospace, and System Engineering, Korea Advanced Institute of Science and Technology, Science Town, Daejeon 305-701, Korea

Hoon Huh1

School of Mechanical, Aerospace, and System Engineering, Korea Advanced Institute of Science and Technology, Science Town, Daejeon 305-701, Koreahhuh@kaist.ac.kr

Se-Ho Kim

School of Automotive, Industrial and Mechanical Engineering, Daegu University, Jillyang, Gyeongsan, Gyeongbuk 712-714, Korea

1

Corresponding author.

J. Eng. Mater. Technol 129(3), 397-406 (Jan 16, 2007) (10 pages) doi:10.1115/1.2744399 History: Received April 04, 2006; Revised January 16, 2007

In this paper, an optimum design is carried out with finite element analysis to determine process parameters which reduce the amount of springback and improve shape accuracy of a deep drawn product with the channel shape. Without springback simulation usually performed with an implicit solving scheme, the study uses the amount of stress deviation through the sheet thickness direction in the deep drawn product as an indicator of springback. The simulation incorporates the explicit elasto-plastic finite element method for calculation of the final shape and the stress deviation of the final product. The optimization method adopts the response surface methodology in order to seek the optimum condition of process parameters such as the blank holding force and the draw-bead force. The present optimization scheme is applied to the design of the variable blank holding force in the U-draw bending process and the application is further extended to the design of draw-bead force in a front side member formed with advanced high-strength steel (AHSS) sheets made of DP600. Results demonstrate that the optimum design of process parameters decreases the stress deviation throughout the thickness of the sheet and reduces the amount of springback of the channel shaped part. The present analysis provides a guideline in the tool design stage for controlling the evolution of springback based on the finite element simulation of complicated parts.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic diagram of the optimization with the response surface methodology: (a) optimization procedure; and (b) sequential response surface methodology (24)

Grahic Jump Location
Figure 2

Geometric description of the tooling for the U draw-bending process: (a) geometric description; and (b) finite element mesh

Grahic Jump Location
Figure 3

Variation of variables during the optimization process of BHF: (a) objective function and constraint; and (b) design variable

Grahic Jump Location
Figure 4

Comparison of the stress deviation through the thickness integration points: (a) before optimization; and (b) after optimization

Grahic Jump Location
Figure 5

Definition of the springback angle and the radius of curvature of side wall after springback (25)

Grahic Jump Location
Figure 6

Deformed shape of the blank after the springback analysis in the U draw-bending process: (a) before optimization; and (b) after optimization

Grahic Jump Location
Figure 7

Variation of variables during the optimization process with different number of integration points: (a) objective function; and (b) design variable

Grahic Jump Location
Figure 8

Comparison of the stress deviation with the eleven integration points along the thickness direction: (a) before optimization; and (b) after optimization

Grahic Jump Location
Figure 9

Deformed shape of the blank after the springback analysis in the U draw-bending process when 11 integration points are used: (a) before optimization; and (b) after optimization

Grahic Jump Location
Figure 10

Description of the outer panel in a front side member: (a) final product model; and (b) initial setting of tools and the blank for the numerical analysis of punch forming

Grahic Jump Location
Figure 11

Selected design variables and divided design regions for the optimization of draw-bead force

Grahic Jump Location
Figure 12

Variation of variables during the optimization process in the design region 1: (a) objective function and constraint; and (b) design variable

Grahic Jump Location
Figure 13

Location of the designated sections used for the comparison of optimized results

Grahic Jump Location
Figure 14

Comparison of the stress deviation through the thickness integration points along the designated section: (a) along the 1-1′ (before optimization); (b) along the 2-2′ (before optimization); (c) along the 1-1′ (after optimization); and (d) along the 2-2′ (after optimization)

Grahic Jump Location
Figure 17

Comparison of the springback amount along the designated sections: (a) along the 1-1′; (b) along the 2-2′; and (c) along the 3-3′

Grahic Jump Location
Figure 16

Comparison of the thickness distribution before and after optimization along the designated sections: (a) along the section 1-1′; and (b) along the section 2-2′

Grahic Jump Location
Figure 15

Comparison of the principal strain distribution before and after optimization: (a) initial design; and (b) optimum design

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In