THE TEMPERATURE INFLUENCE ON THE CRITICAL TIME OF CREEP BUCKLING OF THE COLUMN

摘要

The temperature effect on the creep buckling of the axially compressed column is investigated. The numerical analysis is based on the plane stress finite element model of the column. The step by step numerical procedure involving the Newton type iteration correction of a solution is used. The geometric nonlinear analysis is based on the total Lagrangian formulation of equations. The material nonlinearity is introduced using the thermo-elastic-plastic and creep material model. The components of the second Piola-Kirchoff stress tensor are evaluated using the 'effective stress function' algorithm. The critical time of creep buckling is determined as the time it takes for divergence of the Newton type iteration process. This time corresponds to the fast increase of the central normal deflection of the column. This normal deflection is caused by the initial imperfection. Based on the numerical analysis the critical time of creep buckling is found to increase given the temperature effect for materials with temperature-independent properties. Conversely, the critical time decreases when Young's modulus decreases with increasing the temperature.