外侧壁厚减薄和横截面发生畸变是薄壁管材弯曲过程中的主要缺陷，严重影响弯管的成形质量。薄壁管绕弯成形过程中芯棒对弯管的成形质量影响非常大。采用动态有限元平台ABAQUS/Explicit建立与实际相符的薄壁圆管绕弯模型，分析芯棒种类、芯棒的直径、芯棒的伸出量和芯棒与管材内部摩擦对管材弯曲成形质量的影响，结果表明：万向芯棒在控制管材截面椭圆畸变率方面比圆柱芯棒有较大的优势；为保证管材的成形质量，芯棒的直径和伸出量都应控制在一定范围内；芯棒与管材内部的摩擦应越小越好。并且在全自动数控弯管机DW18CNC上做了大量的实验，实验结果与分析结果相吻合，为实际生产中芯棒参数的选择提供了理论依据。%Outwall-thinning and the cross-section deformation are the main defect in the thin-walled pipe bending process ,influen-cing bend forming quality seriously .Mandrel has a great influence to the quality of the pipe in the thin-walled pipe bending process.The thin-walled pipe bending model ,which matches to the actual ,is built by ABAQUS/Explicit to analyze several factors influencing the quality of the pipe bending such as the mandrel ’ s type,the diameter of the mandrel ,the protrusion of the mandrel and the mandrel and the friction with internal of the pipe .The results show that the universal mandrel has a great advantage in controlling the deformation of the pipe ’s cross-section.In order to ensure the quality of the tube bending ,the diameter of the man-drel and the protrusion of the mandrel should be controlled in a certain range ,mandrel with the pipe internal friction should be as small as possible .A lot of experiments have been done on the DW 18 CNC,which is an automatic CNC pipe bending machine .The experimental results and the results of the analysis are consistent ,which provide a theoretical for the parameters selection of the mandrel .
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