Embedded Reinforcement and Bond-Slip in the Nonlinear Finite Element Modelling of Reinforced Concrete

[摘要] This thesis concentrates on the nonlinear finite element modelling of two dimensional reinforced concrete structures including bond-slip effects. It deals with three aspects of the numerical computation, i. e. modelling techniques, material behaviour and solution techniques. The modelling techniques concerned the reinforcement and bond-slip. Two embedded reinforcement formulations and one embedded bond-slip model have been developed and implemented, leading to a general model for embedded reinforcement including bond-slip effects. An automatic mesh generation scheme for both concrete and embedded steel bar has been implemented in conjunction with the proposed models. For the material behaviour of structural concrete, the study reviews concrete, bond-slip and reinforcing steel properties. Particular attention is given to the bond-slip mechanism and its experimental observation. Tension-stiffening and shear retention are also studied along with cracking mechanism. Concrete behaviour is reviewed, including failure rules and constitutive relationships. The constitutive relationships used in this study are summarized. The cracking behaviour is modelled using smeared approximations. Particularly, fixed cracking model, strain-decomposed cracking model and swing cracking model have been examined and compared. The nonlinear solution techniques used in this study are modified Newton-Raphson and arc-length procedures along with a line search scheme. A stock of numerical examples are presented, including studies on both fundamental issues in the modelling techniques, and application to practical engineering structures. In this study, it has been shown that finite element representation of structural concrete has become sophisticated. Not only can the reinforcement be modelled properly by using embedded isoparametric reinforced concrete elements including bond-slip effects, but also the material behaviour can be traced properly, usually without great difficulty. The results presented in this study have compared satisfactorily with the experimental results and suggest that the proposed modelling are successful.

[发布机构] University:University of Glasgow

[关键词] Civil engineering