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Abstract: The advantage of tube axial
compressive forming and whether to realize forming process depend on
whether to produce the tearing or buckling failures during the forming
process. Based on minimum energy principle for plastic forming, the
buckling machenism and effects of forming parameters on it are
investigated by theoretical analysis and experiment, and the criterion
for bucking failure is developed which can be used to determine proper
parameters for stable forming. The results show that the effect
parameters of buckling failure includes geometrical parameters, material
properties, and friction condition. The main governing parameter that
controls the success of forming process without buckling is the correct
choice of die radius, and existing a maximum radius and a minimum
radius, in this range no buckling failure happens. With the high value
of material strain hardening exponent n and the low value of the
thickness to diameter ratio, it is possible to prevent buckling failure,
at the same time decreasing the friction condition is helpful to prevent
buckling. The criterion for bucking failure purposed in this paper is
used in tube axial compressive forming process for aluminum tube blanks
with brand No 5052, d0=31.0 mm, 41.0 mm and the results show that
criterion is reliable and practical.
Key words: Tube axial compressive forming Mechanical model of failure
Buckling
CLC No: TG386
国家自然科学基金(59775055)和西北工业大学博士论文创新基金(G14109)资助项目. Received 20020206,
received in revised form 20021210
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