中文摘要：

矫直和弯曲是两个相反的工艺过程,但他们的变形机理是相同的。矫直过程中,矫直力的确定对矫直效果有重要的影响,是矫直过程中重要的参数之一。通过利用DEFORM有限元分析软件对管件弯曲过程中加载平衡力的变化进行数值实验,对成品管（直径为Φ720mm,厚度为δ120mm,长度为1000mm的钢管）的弯曲过程进行数值计算分析,根据塑性状态发展趋势揭示管件加载平衡力的变化规律,为矫直过程中关键参数矫直力的确定提供理论依据。

英文摘要：

Straightening and bending are the two opposite processes but their deformation mechanism is the same.To determine the force impact the straightening effect of the straightening process significantly,which is one of the important parameters in the straightening process.Numerical experiments for changes of load balancing was carried out in pipe bending process by adopting DEFORM finite element analysis software,then numerical analysis was done as well in the pipe bending process（steel pipe with diameter Φ720mm,thickness δ120mm,length 1000mm）.The trend of changing for load balancing of the pipe is revealed based on the plastic state,which provides a theoretical basis for determining the key parameters in the straightening process.