关键词: 非线性, 屈曲, 弧长法, 微分求积单元, 管柱

Abstract: Based on differential quadrature (DQ) element of tubular with a radial constraint,an arc-length incremental iteration method is established.It is used for the post-buckling analysis of tubular in a deviated well bottom.Detailed iteration steps and method of determining initial values of iteration are given.Iterative calculations are carried out for nonlinear buckling of tubular under various end lateral constraints in deviated wells.Numerical results are compared with approximate analytical solution,experimental data and numerical results obtained with purely incremental methods in literature.It shows that the developed method overcomes difficulties encountered in finite element method in dealing with tubular weight.At the same time,it is capable to adjust automatically increment step and trace complex path in the space load/displacement of tubular nonlinear post-buckling.The method is of high efficiency,good convergence,easy to implement.It can be used to analyze nonlinear buckling of tubular in deviated wells.

Key words: nonlinear, buckling, arc-length method, differential quadrature element, tubular