Nonlinear three dimensional finite element analysis of reinforced concrete hollow beams

This research work which summed up to this dissertation describes three dimension nonlinear finite element model expediency of the analysis the reinforced concrete beams with hollow cross section and also solid resist monotonic loading. A well-known software ANSYS its finite element pioneered has been used. The advantages of the three dimension finite element model create a full concept about the model in terms of deformation, and critical areas. Among the two methods that representing the cracks, a discrete model has been used. The eight nodes isoperimetric brick element called (SOLID 65) used to model concrete body. While using (LINK 180) three dimension finite strain spar element for modelling the flexural and shear reinforcements. The base plates for each loading point and supporting has been ideally obtained by using (SOLID 185) three dimension structural solid element. For symmetry reasons, a half specimen of the beams is considered in the analysis to reduce computational time and computer. Many types of reinforced concrete hollow beams have been analyzed and the solution of finite element was compared with the data from lab work. Several parametric works were implemented. The effect of some important finite element and material parameters like distribution of mesh, density and effects of mesh size on accuracy of three dimension finite element model results accomplished to look their effects. The analysis results showed that the behavior of the modeled specimen can be clarified by the load-deflection curves at center of beam in addition to the yielding reinforcement occurrence an appropriate agreement with the compared lab test data. At the last presenting the maximum tolerance between the modeled sections and its corresponding experimented one were 6.8%.