In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept ＂critical point on the contact boundary＂ was proposed...In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept ＂critical point on the contact boundary＂ was proposed and the coordinates of the critical point were solved. The equivalent contact section area was represented and the mean roll radius was determined. The validity of this model was examined by alloy bar rolling experiment and rigid-plastic FEM simulation. Compared with the existing models, the mean roll radius obtained by this model is similar to experiment data.展开更多
针对弯曲段套管抗挤强度随井眼曲率变化规律问题,利用材料力学理论将弯曲段套管等价为均布载荷作用下的弯曲梁模型,根据拉梅厚壁筒理论和强度理论得到套管抗挤强度公式.借鉴扁化变形在圆管类结构中的研究思路,将其拓展到套管抗挤强度分...针对弯曲段套管抗挤强度随井眼曲率变化规律问题,利用材料力学理论将弯曲段套管等价为均布载荷作用下的弯曲梁模型,根据拉梅厚壁筒理论和强度理论得到套管抗挤强度公式.借鉴扁化变形在圆管类结构中的研究思路,将其拓展到套管抗挤强度分析,对比分析是否考虑扁化效应下四种规格套管不同井眼曲率下的抗外挤强度.研究表明,套管轴向应力随井眼曲率基本呈线性变化;套管抗挤强度随井眼曲率的增加非线性下降.井眼曲率为2o/30 m时,是否考虑套管扁化变形得到的51/2"×10.54 mm P110套管抗挤强度误差为12.8%;井眼曲率为12o/30 m时,误差46.9%.井眼曲率为2o/30 m时,41/2"×9.65 mm TP140V套管抗挤强度误差11.9%;井眼曲率为12o/30 m时,误差44.7%.可见,考虑扁化变形后套管抗挤强度小于未考虑扁化变形情况;井眼曲率不大时,两种算法的差距较小,随着井眼曲率的增加,套管扁化变形对套管抗挤强度的影响不能忽略.展开更多
文摘In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept ＂critical point on the contact boundary＂ was proposed and the coordinates of the critical point were solved. The equivalent contact section area was represented and the mean roll radius was determined. The validity of this model was examined by alloy bar rolling experiment and rigid-plastic FEM simulation. Compared with the existing models, the mean roll radius obtained by this model is similar to experiment data.
文摘针对弯曲段套管抗挤强度随井眼曲率变化规律问题,利用材料力学理论将弯曲段套管等价为均布载荷作用下的弯曲梁模型,根据拉梅厚壁筒理论和强度理论得到套管抗挤强度公式.借鉴扁化变形在圆管类结构中的研究思路,将其拓展到套管抗挤强度分析,对比分析是否考虑扁化效应下四种规格套管不同井眼曲率下的抗外挤强度.研究表明,套管轴向应力随井眼曲率基本呈线性变化;套管抗挤强度随井眼曲率的增加非线性下降.井眼曲率为2o/30 m时,是否考虑套管扁化变形得到的51/2"×10.54 mm P110套管抗挤强度误差为12.8%;井眼曲率为12o/30 m时,误差46.9%.井眼曲率为2o/30 m时,41/2"×9.65 mm TP140V套管抗挤强度误差11.9%;井眼曲率为12o/30 m时,误差44.7%.可见,考虑扁化变形后套管抗挤强度小于未考虑扁化变形情况;井眼曲率不大时,两种算法的差距较小,随着井眼曲率的增加,套管扁化变形对套管抗挤强度的影响不能忽略.
