Non-linear Finite Element Analysis Of Reinforced Concrete Frames

Non-linear Analysis of Reinforced Concrete FramesThe parameters that influence the behavior of reinforced concrete frame structures are discussed and modeled. This thesis fully concentrated on the material non-linearity, though the geometrical non-linearity is discussed partially. The material non-linearity constitutive relations of reinforced concrete sections are formulated. The non-linear relationship of moment-curvature and moment-flexural rigidity of a section is modeled.A finite element computer program, in Fortran 77 language, is developed for analysis of reinforced concrete frame structures. Sample numerical examples are done to demonstrate its validity, reliability and usefulness.The non-linear behavior of reinforced concrete frames is investigated using the model presented in this study. Linear and Non-linear case of frame structures are analyzed, and the non-linear analyses are compared and contrasted with American code of practice.The objectives and approach of this study is clearly presented and after thoroughly study and investigation, conclusions and recommendations are drawn.It is determined that with accurate knowledge of the complete stress-strain curve of concrete in compression , steel in tension, and with an iterative computerized non?linear method, it is possible to predict the entire moment-curvature, moment-flexural rigidity and axial rigidity relation ship of a cross-section of a structure member.It is concluded that material non-linearity plays the major role in controlling the behavior of frames .Therefore reasonable results can be obtained by considering material non-linearity only in the analysis of some cases: e.g., short frames under vertical loads.