大转动梁的几何非线性分析讨论

本文借助Ｌａｇｒａｎｇｅ（Ｔ．Ｌ．）法、修正的Ｌａｇｒａｎｇｅ（Ｕ，Ｌ，）法及带有动坐标的迭代法求解梁的几何非线性问题，说明了各自的特点，澄清了若干基本概念。指出动坐标方法实质上就是Ｕ．Ｌ．法，它适合于分析具有大转动梁的问题，并可方便地推广到大转动的板壳问题。同时指出对于几何非线性问题，可以不必区分Ｃａｕｃｈｙ应力和Ｋｉｒｃｈｈｏｆｆ应力。

Discussion of analysing of geometric non-linear beams with large rotations

The geometric non-linear problems of beams are solved by means of Lagrange's,updated Lagrange's method and iteration method with moving coordinates,Their peculiarities are shown.A few basic concepts are cleared.The method with moving coordinates in fact is updated Lagrange's method which is suitable for analysing beams with large rotations and is easy to ex-tend to solve plate and shell problems with large rotations.It is also shown in this paper that it is not necessary for geometric non-linear problems to distinguish between Cauchy stress and Kirch-hoff stress