摘要
充液剪切弯曲方法能够整体成形相对弯曲半径小于0.5的极小半径管,内压和补料量对其成形精度有着重要的影响.采用实验的方法研究了在恒定内压下,不同补料量对5A02铝合金管材充液剪切弯曲成形过程截面畸变、圆角大小和壁厚分布影响,并通过数值模拟深入研究了补料量对厚向应变的影响.研究结果表明:补料比(补料量和切向位移之比)小于1.2时可以成形管件精度良好.补料比为1.3时,靠近第一弯角的位置产生截面畸变,不圆度为2.2%.补料比对第一弯角外侧圆角影响明显,当补料比由1提高到1.2时,圆角减小50%由4.5 mm减小至2.25 mm.随着补料比的增加,内外侧壁厚均增大.内外两侧最大增厚分别由27.47%和26.67%增加到38%和34.67%,最大减薄分别由14.53%和6.64%降低到8.73%和5.8%.补料比对外侧壁厚影响大于内侧.由此可知,补料量增加,有利于外侧圆角的成形和改善成形管件的壁厚分布,但补料量过大,易造成截面畸变.
The effects of feeding stroke on cross section distortion,corner radius dimension and thickness distribution of 5A02 shear hydro-bent tube are studied by experiment under the condition of constant internal pressure.Nnumerical simulation further conducted to analyze the effect of feeding on thickness strain.The results show that when the feeding ratio（axial feeding stroke over transversal stroke）is smaller than 1.2,the ultra-small bending tube can be successfully manufactured.While it is up to 1.3,the cross section distortion reaches 2.2% at the first corner.When the feeding ratio rises from 1 to 1.2,the extrados corner radius is varied from 4.5mm to 2.25mm and decreased by 50%.The thickness is increased with the increasing of the feeding ratio.The maximum thickening is increased from 27.47% at intrados and 26.67% at extrados to 38% and 34.67%,and the maximum thinning is decreased from 14.53% and 6.64% to 8.73% and 5.8%,respectively.It can be concluded that the corner radius dimension and thickness distribution are improved with the increase of feeding ratio,but the cross section distortion is easily generated if the feeding ratio is too large.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2013年第2期67-71,共5页
Materials Science and Technology
基金
国家自然科学基金资助项目(51075097)
关键词
极小半径管
剪切弯曲
补料量
成形精度
ultra-small bending radius
shear hydro-bending
feeding stroke
shape accuracy
