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Abstract: The
stress distribution and deformation pattern of the corner are analyzed
by mechanical analysis and numerical simulation, and then the mechanism
of thinning and cracking at the transition region is disclosed. It is
presented that the material at the transition region is the easiest
region to satisfy plastic yielding conditions and produce thickness
compressive strain. Therefore severe thinning deformation is easy to
occur at the transition region and when the ratio of wall thickness to
corner radius is bigger than 0.5, the difference of yielding conditions
between straight side and corner is more significant so that the
deformation nonuniformity is increased, and is easier to induce the
excessive thinning and cracking. The result is useful for lightweight
part design and process design of tube hydroforming (internal high
pressure forming) to improve product quality.
Key words: Tube
hydroforming Transition corner forming Lightweight component Local
thinning Fracture
CLC No: TG306
国家自然科学基金资助项目(50375036). Received
20050704, received in revised form 20060126
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