Research Papers

Investigation and Correction of Surface Distortion in Dies With Typical Depression Features

[+] Author and Article Information
Hui-Ping Wang

 Staff Researcher GM Research and Development Center, Mail Code 480-106-224, 30500 Mound Road, Warren, MI 48090hui-ping.wang@gm.com

Kunmin Zhao, Ping Hu, Zhengchun Fu

Jing-Ru Bao

 Dalian University of Technology, No. 2 Linggong Road, Dalian, 116024 Chinajingrubao@gmail.com

J. Manuf. Sci. Eng 133(4), 041004 (Jul 20, 2011) (10 pages) doi:10.1115/1.4004405 History: Received December 06, 2009; Revised June 08, 2011; Published July 20, 2011; Online July 20, 2011

Surface distortions are frequently introduced into Class “A” surfaces during various sheet metal forming operations such as drawing, trimming, and flanging. The origins of these surface distortions have not been well understood. The scope of this research is to investigate the distortion that occurs in the draw operation and to find effective and practical corrective methods. Five geometric parameters are first identified to represent typical depression features in automobile outer panels. Experimental dies are then designed to reflect various combinations of these five geometric parameters with the assistance of numerical simulations to ensure that the dies can make parts free of major defects such as splits and wrinkles. Surface distortions are observed in our stamping experiments and various techniques are used to measure and record the distortions for further mathematical analysis. Historical data of strains and deflections in distortion areas are collected through real-time measurement. The effects of three geometric parameters on distortion are analyzed using a full factorial DOE model. A geometry morphing program based on UG-NX platform is developed. The program is used to morph the die face in the distortion areas. Finally, three approaches that aim to correct distortions are tried out and the die morphing proves to be a practical and effective method.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 9

(a) Stoned specimen with αP  = 60 deg, RP  = 20 mm, and H = 5 mm. (b) Stoned specimen with αP  = 90 deg, RP  = 20 mm, and H = 5 mm. (c) Stoned specimen with αP  = 120 deg, RP  = 20 mm, and H = 5 mm.

Grahic Jump Location
Figure 10

Distortion characteristics of specimen with αP  = 60 deg, RP  = 20 mm, and H = 5 mm

Grahic Jump Location
Figure 11

Main effect of depression depth, plan view radius, and plan view angle on distortion magnitude

Grahic Jump Location
Figure 12

A surface contour from the laser scanning

Grahic Jump Location
Figure 13

Draw-in comparison between experimental measurement and numerical simulation (unit: mm)

Grahic Jump Location
Figure 14

(a) Surface contour from the numerical simulation. (b) Zebra lines of the predicted numerical surface

Grahic Jump Location
Figure 15

Strain histories from measurement and simulation

Grahic Jump Location
Figure 16

Displacement history from measurement

Grahic Jump Location
Figure 17

Revised upper die for good bearing

Grahic Jump Location
Figure 18

Laser scan of the part with proper die bearing

Grahic Jump Location
Figure 19

Stamped part for a blank with stress-relieving holes

Grahic Jump Location
Figure 20

Surface distortion of a part when stress-relieving holes are designed in its blank

Grahic Jump Location
Figure 21

Geometry morphing algorithms: (a) original B-spline surface; (b) morphed surface based on Gaussian function; (c) morphed surface based on parabolic function; (d) morphed surface based on quadratic spline function

Grahic Jump Location
Figure 22

Surface morphing program based on UG-NX platform

Grahic Jump Location
Figure 23

Morphed low die (four corners)

Grahic Jump Location
Figure 24

Surface contour of the specimen stamped with the morphed die

Grahic Jump Location
Figure 1

Typical surface distortion in automotive skin panels

Grahic Jump Location
Figure 2

Illustration of geometric variables and die setup

Grahic Jump Location
Figure 3

Plan view of four basic depression shapes

Grahic Jump Location
Figure 4

Cross-sectional view of the die design with depression shape in center

Grahic Jump Location
Figure 5

Three-dimensional wireframe view of the solid die design

Grahic Jump Location
Figure 6

(a) Upper die assembly. (b) Lower die assembly. (c) 16 pairs of interchangeable die inserts.

Grahic Jump Location
Figure 7

Illustration of displacement sensors installed in low die

Grahic Jump Location
Figure 8

Representative stamped specimens



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