Nonlinear Finite Element Analysis Of RC Transfer Plates

RC transfer plates used in high-rise buildings are generally fallen into the category of median thick or thick plates. Therefore, they should be treated as Mindlin-Reissner plates. Nonlinear analysis of such plates involve problems of finite element treatment of a plate as well as constitutive modeling of concrete materials in pre- and pro- cracking conditions. In this thesis, available research works are firstly summarized and comments are given. Then all the related problems are investigated. Especially, constitutive behavior of cracked concrete are studied and a constitutive model in a consistent form is proposed. Biaxial cracking are modeled. The main works are summarized as follows:1. The assumed-strain finite element which was proposed by Huang, H. C. is used to avoid shear locking and zero energy mode. It has been proved that this element is applicable to thin plate and thick plate as well. It is simple and effective.2. The underlying concept and typical models based on Hillerborg's fracture energy principle are discussed. Based on a extensive study of the concrete failure behaviors under multiaxial conditions, the concepts of brittle cracking failure and ductile cracking failure are developed. Then, the tension failure and compression failure are unified considered from the point of view of fracrure energy principle. By using the basic concept of modeling of strain localization, a consistent formulation has been developed for modeling strain-softening process both in tension and compression in the general three-dimensional case.