管材绕弯变形的理论与实验分析

Theoretical and Experimental Study on the Deformation of Pipe Rotary-draw Bending

针对管材绕弯成形的受力与变形特点,进行了理论与实验研究.应用塑性有限元方法分析了绕弯的主要工艺参数对成形后管材壁厚变化及截面椭圆度的影响,结合实验分析了变形区不同位置的椭圆度及壁厚的减薄情况.研究表明:R/D越小,变形越大,壁厚减薄也越大,而相对壁厚t/D对壁厚减薄影响不大;另外,芯棒的尺寸及位置对壁厚减薄率及截面椭圆度影响较大.

Deformation of pipe during rotary-draw bending is studied theoretically and experimentally. The effect of main technical parameters on the change of wall thickness and section flattening are analyzed with plastic FEM software, meanwhile the variety of wall thickness and section flattening in different location of pipe are studied experimentally. The result shows： the smaller R/D, the bigger the wall thickness change. The effect of t/D on wall thickness change is weak. The dimension and position of the mandrel have a big impact on wall thickness and section flattening. The conclusion is helpful to improve the quality of the rotary-draw bending of pipe.