Elastic-Plastic Non Linear Behaviors of Suddenly Loaded Structures

Problem statement: The adaptively shifted integration technique was applied to the elasticplastic analysis of framed structures under dynamic loading. Approach: This study used analysis of linear beam element, the reshifting of the of the integration points in the element is conducted in order to attain higher accuracy. Results: In nonlinear finite element analysis by the ASI technique, the highest computational efficiency has been achieved by shifting the numerical integration points for evaluation of stiffness matrices of linear Timoshenko beam element. A computer program has been Written by VBASIC for solve the problem of the steel frame, results of numerical examples demonstrate the validity of the computer program and study many parametric study, such as Time step and Mass of the structure. Conclusion/Recommendations: In the elastic analysis there is no distinction between the ASI technique and the conventional finite element method, but for elasticplastic nonlinear analysis under dynamic load Adaptive Shifted Integration (ASI) technique is capable of predicting with reasonable accuracy the behavior of steel frame structures.