基桩屈曲的几何非线性有限元分析

将桩身视为空间受力的梁单元，利用更新的拉格朗日坐标体系考虑梁单元的几何非线性；并采用弧长控制法求解有限元非线性方程组，进行基桩屈曲的几何非线性有限元分析。利用Matlab语言编制了相应的计算程序，将某现场木桩压屈试验实测屈曲临界荷载与理论分析比较，吻合良好。大量计算分析表明，桩周土地基系数、基桩埋入比、桩身材料和基桩长细比是影响基桩屈曲荷载大小的重要因素，在设计和施工中都应重视和考虑。

Geometrically nonlinear finite element analysis of pile buckling

Regarding the pile shaft as a spatial beam element, the geometrical nonlinearity of this element has been considered with the updated Lagrangian coordinate system. And the geometrically nonlinear finite element analysis of pile buckling has been carried out with the calculation of finite element nonlinear equation set by arc-length method. With the corresponding calculation program by Matlab, the calculation result meets well the measured critical load in field buckling experiment of woody piles. At the same time, a great deal of calculation analysis indicates that the foundation ratio of soil around pile, embedding ratio, material and slenderness ratio of pile are important factors that affect the buckling load of pile, which should be regarded and considered during design and construction course.