Title: Analysis of growth and disappearance of surface deflection in press forming of large-sized autobody panels

Authors: H. Ishigaki, I. Okamoto, N. Nakagawa, K. Arima

Addresses: Toyota Motor Corp., Toyota-shi, Japan. ' Toyota Motor Corp., Toyota-shi, Japan. ' Toyota Motor Corp., Toyota-shi, Japan. ' Toyota Motor Corp., Toyota-shi, Japan

Abstract: The forming severity of large-sized autobody panels is assessed not only on the basis of the fracture, but also by the surface deflection which is a surface defect concave or convex to expected normal shape. For avoiding the surface deflection, the fitting behaviour of the die to the panel, and fittability of material are investigated. The materials properties constituting the fittability are mainly the yield point, the strain-hardening coefficient in the range of small strain (n*0.02) and sometimes the n-value, the normal plastic anisotropy (r-value) corresponding to the deformation state. The shape of the blankholder surface strongly affects the growing behaviour of the surface deflection, and the step draw greatly affects the decreasing behaviour of the surface deflection.

Keywords: body panel formation; mechanical properties; surface deflection; vehicle design; press forming; car body panels.

DOI: 10.1504/IJVD.1985.061342

International Journal of Vehicle Design, 1985 Vol.6 No.2, pp.240 - 256

Published online: 25 May 2014 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article