受径向约束管柱非线性屈曲的DQE法

基于圆柱面坐标,导出了受径向约束管柱屈曲的平衡微分方程,给出了详细的斜直井内管柱屈曲分析的DQE（differential quadrature element）法列式.用DQE法对斜直井内管柱的非线性屈曲进行了计算分析.结果表明：本文的计算结果与实验结果吻合;工程中受径向约束管柱的屈曲问题,由于受压段的管柱一般很长,因此是一个局部非线性稳定性问题,屈曲首先是从下端开始发生,然后随着上端载荷的增加,逐渐向上扩展的.本文所建立的DQE法可以方便地用于求解受径向约束管柱的非线性屈曲问题.

The DQE Method for Analyzing the Nonlinear Buckling of Tubular Under Radial Constraints

The equilibrium equation of tubular subjected to radial constraints is deduced based on the cylindrical coordinate system. Detailed expressions in terms of Differential Quadrature Element(DQE)Method in analyzing the buckling of tubular within deviated wells are given. The nonlinear buckling of tubular is then analyzed. Numerical results indicate that the computed data are closed to the experimental ones. It is seen that the buckling of tubular subjected to radial constraints in practice is generally a local buckling problem, since the length of tubular under compression is usually long. The buckling starts from the lower end then propagates upward with the increase of applied axial load at the upper end. The established DQE method can be conveniently used for solving the nonlinear buckling of tubular under radial constraints.