Formability Principles of Linear-weld-line Tailor-weld Blanks (TWBs) with Different Thickness ratios

TONG Zhengguo¹  LIN Jianping¹  TIAN Haobin¹  SMITH Lorenzo M²  NI Feng³

(1. School of Mechanical Engineering, Tongji University, Shanghai 200092;
2. School of Computer Science and Engineering, Oakland University, Rochester, 48309-4401, USA;
3. Shanghai Volkswagen Automotive Company Ltd., Shanghai 200050)

Abstract: According to the forming theory of hemisphere bulge of tailor-weld blanks (TWBs) and the classic mechanics theory, based on the hemisphere bulge test of liner-weld-line TWBs with different thickness ratios for mild steel, the relationship between the thickness ratio of liner-weld-line TWBs and the formability is analyzed. Meanwhile, the mechanics model for the correlation between the thickness ratio and formability is proposed. Combining the physical experiment and finite element simulation model, the relationship between the weld-line movement and thickness ratio, as well as the relationship between the bulge height and the thickness ratio, are studied. The formability results of TWBs with different thickness ratios are observed. The mechanism the weld-line movement and the decrease of formability is analyzed. The rules among the thickness ratio, weld-line movement and forming height are summarized, which can provide theoretical guidance for the production in practice.

Key words: Tailor-welded blanks  Thickness ratio  Dome test  Finite element method  Mechanics model  Movement of weld line Forming limit

CLC No: T

Received 200770527, received in revised form 20071209

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