芯模对双脊矩形管绕弯成形截面畸变的影响

采用芯模可有效减小双脊矩形管绕弯成形过程中的截面畸变,并提高弯曲管件的成形精度.因此基于ABAQUS/Explicit有限元软件,建立了可靠的双脊矩形管绕弯成形三维有限元模型,研究获得了芯模对截面畸变的影响规律.结果表明:沿截面宽度、高度、外脊宽度和双脊高度的最大变形量均位于管坯的棱线上;沿弯曲方向,管坯宽度、高度和双脊高度的最大变形量均出现在60°附近截面上,外脊宽度的最大变形量出现在20°附近的截面上;随着芯头个数的增加、芯头和管坯间隙的减小及其摩擦因数的减小,管坯宽度、高度和外脊高度的最大变形量均减小,而外脊宽度的最大变形量略有增大或基本不变.

Influence of mandrel on cross section deformation of double-ridge rectangular tube in rotary-draw bending process

Mandrel can reduce the cross-section distortion in rotary draw bending process and improve the forming accuracy of double-ridge rectangular tube. A reliable three-dimensional FE model of double-ridge rectangular tube in rotary-draw bending is established under the ABAQUS/Explicit environment, and the effects of mandrel on cross-section deformation are obtained. The results show that the maximum deformation of width, height, outer ridge width and double-ridge height along the section is located on the edge of tube. And the maximum deformation of width, height and double-ridge height appears near the 60° bending section, while the maximum deformation of outer-ridge width appears near the 20° bending section along the bending direction. With the increase in number of cores and the decrease of the clearance and friction coefficient between mandrel and tube, the maximum deformation of width, height and double-ridge height decreases, while the maximum deformation of outer-ridge width slightly increases or has almost unchanged.