Nonlinear Finite Element Analysis And Design Researching Of Reinforced Concrete Deep Beams With Openings

The behavior of reinforced concrete(RC) deep beams is different from shallow beams and the situation becomes more complex since the presence of web openings. All codes presented are short of explaining the exact behavior of deep beams and the scope of application. However, no code provision exists for the deep beams with openings and there are few studies on the nonlinear analysis of them. In this thesis, nonlinear finite element analysis method is used to simulate RC deep beams with openings and research the design of them. And the primary results are as follows.Based on the successful validation of the ability of the selected nonlinear finite element model, a series of RC deep beams with openings, are analyzed, and the differences between simulation results and the test ones, are explained. The strain distribution of the studied deep beam at failure, is extracted and proved nonlinear, so as the stress distribution. It finds out that the stress distributions keep a corresponding relationship with the strut-and-tie models from the genetic evolutionary structural optimization(GESO) algorithm, for the same deep beams.After a group of simulation comparison to three deep beams,one of which are designed by elastic stress graphical method in this thesis and the others are studied tests designed by internal forces method and strut-and-tie model(STM) method respectively, the last method is proved most optimized among the present design methods, by comparative analyses of mechanical properties, such as loading capacity, structure ductility, stress field and so on.On the basis of distributions and variations of nonlinear stress for the deep beams with openings, a new nonlinear design method, generally applying to both deep beams with double or partial openings, is presented and matches the nonlinear properties of deep beams. What’s more, it is proved more reasonable and more economical and effective than the other methods in terms of design theory and design results respectively. Undoubtedly, it provide s a useful reference for the design of deep beam with openings.A parametric study is systematically conducted to investigate behaviours of deep beams various web opening shapes or reinforcement layouts respectively. The important effects of the two main factors are evaluated after a further understanding of the structural behaviors and mechanism of them. Then, some recommendations are summarized on the engineering application to the deep beams with openings.