0Cr18Ni9管材大曲率无芯弯曲横截面畸变研究

Research on cross section distortion of 0Cr18Ni9 tube in no-mandrel bending with large curvature

为了提高管材弯曲成形性及弯曲精度,基于ABAQUS有限元平台,建立了管材大曲率无芯弯曲有限元模型,模拟了管材大曲率无芯弯曲过程,研究了弯曲角、弯曲速度以及初始管材壁厚对管材大曲率无芯弯曲横截面椭圆畸变的影响,同时进行了相关实验验证。结果表明:模拟与实验结果吻合较好,各弯曲条件下二者误差均在一合理范围内,验证了有限元模型的可靠性;最大横截面短轴变化率随弯曲角度及弯曲速度的增大而增大,随管材初始壁厚减小而增大;弯曲角度及管材初始壁厚对最大横截面短轴变化率影响较大而弯曲速度对其影响相对较小;通过选择合适的弯曲工艺,可弯制出满足要求的大曲率弯管。

In order to improve the bending formability and bending accuracy of tube,a finite element model was established based on the ABAQUS finite element platform,and the bending process of large curvature and no-mandrel of the tube was simulated.The effect of bending angle,bending speed and initial wall thickness of tube on elliptical distortion of cross section with large curvature and no-mandrel bending process for 0 Cr18 Ni9 tube was studied.At the same time,the experimental verification was carried out.The results show that the simulation results are in good agreement with the experimental results,and the errors under all bending conditions are within a reasonable range,which verifies the reliability of the finite element model.The maximum cross section minor axis variation rate increases with the increase of bending angle and bending speed,while increases with the decrease of initial wall thickness of tube.The bending angle and the initial wall thickness of tube have a great influence on the maximum cross-section short axis variation rate,while the bending speed has a relatively small influence on it.By selecting suitable bending process,the qualified bent tube with large curvature can be produced.