可膨胀管膨胀过程三维有限元数值模拟

3-D FEM numerical simulation of the expansion process of expandable tube

为合理设计膨胀工具及制订膨胀工艺,采用三维弹塑性接触问题有限单元法,建立了实体可膨胀管膨胀过程的三维非线性接触问题有限元分析模型.通过对所建模型的求解,对可膨胀管膨胀过程中膨胀变形力、套管膨胀后的残余应力及轴向位移、膨胀工具模角的关系进行了深入细致的研究,找出了膨胀管与膨胀工具在不同的接触条件、可膨胀管在不同的内径膨胀率及不同的壁厚条件下,各参数之间相互制约的变化规律.通过实验测得的膨胀变形力与用本模型求得的结果符合得很好,相对误差仅为0.65%,完全可以满足实际工程的要求.

In order to reasonably design expansion tool and work out expansion technology,a 3-D FEM model of solid expandable tube is established.Through solving the model,the relationships between expansion deformation force,residual stress and axial displacement and the modular angle of expansion tool are obtained under different contact conditions of expandable tube with expansion tool,different wall thicknesses of expandable tube and different expansion ratios of the inner diameter of expandable tube.The expansion deformation force calculated by the model tallies well with that measured by experiment,the relative error between them is 0.65% only,which can meet the requirement of practical construction.