The internal pressure of the process was studied theoretically and experimentally. The external load character and internal stress character of tube hydroforming were discussed first. Then, according to the characters...The internal pressure of the process was studied theoretically and experimentally. The external load character and internal stress character of tube hydroforming were discussed first. Then, according to the characters, the function and classification of internal pressure were presented in general. Base on the stress analysis, its effect on the yield criterion and calculation formula were also researched and derived. To verify the correction of the theoretical analysis and derived formula, experiments with different internal pressures were carried out and the result was compared and discussed. It demonstrates that internal pressure plays an important role in tube hydroforming and theory and formula discussed and derived by this paper are feasible in practice.展开更多
通过宏观形貌检查、材料性能试验、密封面和台肩面的显微形貌观察以及过扭试验等方法分析某失效φ88.9 mm×6.45 mm 110S油管接箍变形事故原因,并通过数学模型计算失效管体工况扭矩。结果表明,此次失效事故是由于在进行解卡和丢手...通过宏观形貌检查、材料性能试验、密封面和台肩面的显微形貌观察以及过扭试验等方法分析某失效φ88.9 mm×6.45 mm 110S油管接箍变形事故原因,并通过数学模型计算失效管体工况扭矩。结果表明,此次失效事故是由于在进行解卡和丢手作业过程中对油管施加的工况扭矩过大,使得接箍台肩面过扭屈服;加之失效油管接箍的井下温度在100℃以上,降低了油管接箍材料的自身屈服强度,同时油管在井下复杂的受力状况及可能出现的螺旋屈曲会进一步加剧接箍台肩面屈服,从而导致接箍台肩变形失效。展开更多
基金This work is supported by the National Natural Science Foundation under grant No.59975021,which was gratefully acknowledged.At the same time,the author also thanks Prof.P.Zeng of Tsinghua University for his kind assistance which is also indispensble in the accomplishment of this paper.
文摘The internal pressure of the process was studied theoretically and experimentally. The external load character and internal stress character of tube hydroforming were discussed first. Then, according to the characters, the function and classification of internal pressure were presented in general. Base on the stress analysis, its effect on the yield criterion and calculation formula were also researched and derived. To verify the correction of the theoretical analysis and derived formula, experiments with different internal pressures were carried out and the result was compared and discussed. It demonstrates that internal pressure plays an important role in tube hydroforming and theory and formula discussed and derived by this paper are feasible in practice.
文摘通过宏观形貌检查、材料性能试验、密封面和台肩面的显微形貌观察以及过扭试验等方法分析某失效φ88.9 mm×6.45 mm 110S油管接箍变形事故原因,并通过数学模型计算失效管体工况扭矩。结果表明,此次失效事故是由于在进行解卡和丢手作业过程中对油管施加的工况扭矩过大,使得接箍台肩面过扭屈服;加之失效油管接箍的井下温度在100℃以上,降低了油管接箍材料的自身屈服强度,同时油管在井下复杂的受力状况及可能出现的螺旋屈曲会进一步加剧接箍台肩面屈服,从而导致接箍台肩变形失效。
