الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
A corotational finite element formulation for two dimensional beam elements with geometrically nonlinear behavior is presented. The formulation separates the rigid body motion from the pure deformation which is always small relative to the corotational element frame. The elastic force vector due to deformation, the stiffness matrices and the mass matrices are firstly computed in the local corotational coordinate system before transformed to the global system. The stiffness matrices and the mass matrices are evaluated using both Euler-Bernoulli beam model and Timoshenko beam model. The comparison between the two models reveals the shear effect during studying thin and thick beams and frames. The nonlinear equilibrium equations are developed using Hamilton’s principle and are defined in the global coordinate system.A MATLAB code is developed for the numerical solution of the nonlinear equations. In static analysis, the code is developed using an iterative method based on the full Newton-Raphson method without incremental loading. While in dynamic analysis, an incremental-iterative method is used based on the Newton-Raphson method and the Newmark direct integration implicit method. Several examples of flexible beams and frames with large displacements, which subjected to either static or dynamic loads, are presented to show the effectiveness and accuracy of the proposed method. Though the method is simple and time saving, it is highly effective and gives sufficiently accurate results.