Calculating Deformation Of 65 Meter High Skylift Using Geometric Non-linear Method

The theory of geometrical non-linear finite element method is researched, which includes equilibrium equation, Lagrange formulation, assembled equations and tangent stiflhess matrix. It is applied in analyzing and calculating static distortion of skylift in virtue of updated Lagrange formulation and iterative method with moving coordinates. The solutions are worked out by increment principle and Newton-Raphson method. The calculation shows that the difference between results of linear method and results of non-linear method is quite obvious. The influence of non-linear solutions on skylift stability can not be neglected. When the outer load increases, the deformation of skylift will have a bigger effect on stability. The calculating results are almost equal whether Newton-Raphson method or its modified form is used, especially with more times of loading, which indicates that essential of the two methods is same.