Advanced nonlinear finite element investigation into structural behaviour of composite beams

This thesis reports the findings of a four year research project using advanced nonlinear finite element modelling to investigate the structural behaviour of various types of composite beams with practical constructional features. The objectives of the research project are: (1) To examine the structural behaviour of simply supported, continuous and semicontinuous composite beams through advanced nonlinear finite element modelling which incorporates the nonlinear deformation characteristics of shear connectors and tensile reinforcement. (2) To provide detailed understanding on the structural behaviour of various types of composite beams based of the results of extensive parametric studies with advanced nonlinear finite element modelling. (3) To develop integrated analysis and design models for composite beams with practical constructional features, and to provide guidance for practical design of composite beams. This project provides detailed understanding on the structural behaviour of simply supported, continuous and semi-continuous composite beams used in modern composite construction. The effects of nonlinear as well as non-ductile deformation characteristics of shear connectors and tensile reinforcement are also studied, which provides in-depth understanding of the effects of the shear connectors and the tensile reinforcement on the overall structural behaviour of composite beams. This extends the design provisions provided in codes of practice, and allows composite beams with material properties and geometrical configurations significantly different from those conventional arrangements to be designed accurately. A number of finite element models are also proposed for the integrated analysis and design of various types of composite beams with practical construction features, which are not readily covered in current codes of practice. This supplements the scope of the current codified design rules and leads to a more 'user-friendly' design of composite beams. Due to the high efficiency of the proposed finite element models, the computational efforts of those models are found to be acceptable in modern design offices. Structural engineers are strongly encouraged to employ the models in their practical work to exploit the full advantages offered by composite construction.