管材无芯弯曲的最小相对弯曲半径  

MINIMUM RELATIVE BENDING-RADIUS OF TUBE-BENDING WITHOUT MANDREL

作　　者：鄂大辛[1] 宁汝新[1] 

机构地区：[1]北京理工大学机械与车辆工程学院,北京100081

出　　处：《机械工程学报》2007年第5期219-222,共4页Journal of Mechanical Engineering

基　　金：北京市重点学科基金资助项目(XK00070424)

摘　　要：为了系统研究管材弯曲的变形实质,进行大量管材无芯弯曲试验。结合管材弯曲成形中外侧管壁材料切向受拉的变形现象,分别对可能发生的集中性拉伸失稳和分散性拉伸失稳变形进行分析。给出与管材力学性能相关,且受拉伸失稳约束的最小相对弯曲半径的计算公式,可用于工艺计算,并对管材弯曲成形设计和工艺分析具有一定的参考价值。通过相应的试验分析指出,由于管材制造所形成的残余应变使得材料在管型状态下所表现的力学性能有一定变化,因此管材弯曲作为二次塑性变形,其真实硬化模数及力学性能参数对弯曲过程中材料的失稳变形和最小相对弯曲半径的计算具有重要影响。In order to study the deforming essence of the tube-bending systemically, a great number of experiments of tube-bending without mandrel are carried out. Integrating the deformation phenomenon that the material of outer wall bears tangential tension, the probable deformation of concentrated and dispersive tensile destabilizing is analyzed respectively. The formula of the minimum relative bending-radius, which is related to mechanical property of the tube and constrained by tensile destabilizing, is concluded. The formula can be used in technique calculation and is helpful to the design of the bending forming of the tube and the technical analysis. Through corresponding experimental analysis, it is pointed out that since the remanent strain generated in tube processing causes some change of the mechanical property of the material in the state of tube shape. Therefore, as the secondary plastic deformation, the practical hardening modulus and the mechanical property parameter of the tube-bending have important influence on the destabilizing deformation of material in the bending process and the calculation of the minimum relative bending-radius.

关 键 词：管材弯曲 切向应变 壁厚变形 硬化模数 

分 类 号：TG386.3[金属学及工艺—金属压力加工]