几何非线性有限元法及干扰能量法在结构稳定分析中的应用

Geometrically Non-Linear FEM and Disturbed Energy Method and Their Applications in Structural Stability Analysis

基于几何非线性理论及著名的稳定性能量判据，推导出用于结构失稳判断的干扰能量法，利用该法确定了压杆的失稳临界状态，研制出几何非线性有限元程序并应用于压杆的大变形计算。两者结果与压杆稳定问题的理论解相符，可用于结构屈曲稳定问题分析。

Based on the theory of geometrical non-linearity and the well-known stability criterion of energy, the disturded energy method for instability evalution of structures is presented in the paper. The instability critical status of an impacted column is determined with the method. An incremental FEM program for geometrically non-linear analysis is developed and applied in the calculation of large deformation of the column. The two results obtained tally with the theoretical solution to the stability problem of the column, proving high accuracy of the method and the program presented, which may be used for structural stability analysis.