Analysis and experiment of cross-section flattening incoreless tube bending  

作　　者：贾美慧 唐承统 刘检华 

机构地区：[1]Key Laboratory of Fundamental Science for Advanced Machining,Beijing Institute of Technology

出　　处：《Journal of Beijing Institute of Technology》2014年第1期37-41,共5页北京理工大学学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(50805009);Twelve Five-Year Plan Basic Research Item of National Defense of China(A2220110008)

摘　　要：In order to predict the flattening rate of the cross-section accurately during the tube ben- ding, the generation principle, the solution and the influence factor of the cross-section flattening were studied. On the basis of the plane-stress and the assumption that the plastic volume is con- stant, three-dimensionai strain formulas were established in consider of the cross-section flattening. Considering the wail-thickness change, the approximate calculation formulas of short axis flattening rate were deduced, with the outer diameter and the inner diameter as parameters. Because different materials have different cross-section flattening rates, a material correction factor was introduced to modify the formula based on experiments. Finally, the validity of the theoretical formulas was proved according to the calculation and the experiment results, which can provide a reference for the forming quality prediction in tube bending.In order to predict the flattening rate of the cross-section accurately during the tube ben- ding, the generation principle, the solution and the influence factor of the cross-section flattening were studied. On the basis of the plane-stress and the assumption that the plastic volume is con- stant, three-dimensionai strain formulas were established in consider of the cross-section flattening. Considering the wail-thickness change, the approximate calculation formulas of short axis flattening rate were deduced, with the outer diameter and the inner diameter as parameters. Because different materials have different cross-section flattening rates, a material correction factor was introduced to modify the formula based on experiments. Finally, the validity of the theoretical formulas was proved according to the calculation and the experiment results, which can provide a reference for the forming quality prediction in tube bending.

关 键 词：coreless tube bending cross-section flattening wall-thickness variation change-rate ofshort axis 

分 类 号：TB302[一般工业技术—材料科学与工程]