单元类型对有限元计算弯管截面畸变及壁厚变化的影响

在1Cr18Ni9Ti管回转牵引弯曲试验的基础上,分别采用实体单元和壳单元进行了相应的有限元模拟。分析2种单元类型的模拟结果后发现,采用实体单元和壳单元都能较好地表现管材的弯曲成形形状及过程,但两者的模拟结果存在差异。实体单元能较为准确地反映弯管的应力应变状态,对弯管横截面畸变的模拟结果更接近于实验值,而在预测弯管壁厚变化及起皱程度时,壳单元更合适。

Effects of Element Types on Cross Sectional Distortion and Wall Thickness Variation in Finite Element Simulation

Based on rotary drawing bending tests of 1Cr18Ni9Ti tubes,finite element（FE）simulations were performed employing solid element and shell element respectively.It is revealed that,both of the simulated results of solid element and shell element can characterize actual tube bending process and performances following bending while there exists a certain discrepancy in two elements.Compared with shell element,solid element may reflect the stress-strain state more accurately and provide a more correct result of cross sectional distortion during the bending operation.But the shell element is more suitable than solid element in predicting wall thickness variation and the severity of wrinkling.