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Abstract: Being of simple shape and can be easily produced,
equilateral frustum shells are often used as initial shells for the
dieless hydroforming of small diameter spherical vessels. But in the
forming process, equator of the shell tends to withdraw inwards and
therefore creates wrinkles here, which badly affects the quality of the
vessel. Pointing to this problem, rigid plastic finite element analysis
is employed to simulate the hydrobulging process of the shell under
internal pressure, then some modifications for the initial shape of the
frustum shell are presented to restrict withdrawing of the equator and
to prevent it from wrinkling. Results of the simulations show that the
modified frustum shell is both simple in shape and effective in
anti-wrinkling, and has the capability to obtain a really round vessel
which is not possible with an equilateral frustum shell.
Key words: Frustum shell Hydrobulging Numerical simulation
CLC No: TG394
福州大学科技发展基金研究项目(XKJ(QD)-0125). Received 20010705,
received in revised form 20020328
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