中文摘要：

三点弯曲压力矫直,是目前规范大型直缝焊管直线度的主要手段。由于大型管件的特殊性,文章基于激光三角法建立了大型管件的挠度测量系统。通过实验,验证了直梁三点弯曲与曲梁三点压力矫直之间的等价关系;根据弹塑性小变形理论,解析了直梁弯曲过程中压下量与管坯卸载弹复后最大挠度的关系曲线,并实验验证了其正确性。该文为大型直缝焊管压力矫直工艺参数制定,提供了理论基础,改变了目前大型直缝焊管生产厂家矫直工艺主要依赖操作人员经验的现状。挠度测量系统的实现,为大型管件智能化矫直,提供了理论指导。

英文摘要：

Three-point pressure bending straightening is the main method to attain the straightness of large longitudinal welding pipe currently.Directing to the special feature of large pipe,a deflection detecting system for large pipe was erected based on the laser trigonometry.The equivalence relationship between the three-point pressure straightening of straight beam and curved beam was verified by experiment.According to the elasto plasticity small deformation theory,the relationship between the deformation and the maximum defection after unloading was analyzed and verified by experiment.The results provide theoretical principle for the formulation of technological parameters in the straightening process,and change the current situation of primarily depending on operator＇s experience.