| Objectives: In order to improve structural accuracy and efficiency of long span composite beam design, an advanced numerical investigation into the structural performance of composite beams with high performance materials and practical constructional features was conducted. After extensive calibration against test data of single and double span composite beams, advanced two and three dimensional finite element models with the following features have been established successfully: i) Geometrical and material non-linearity with initial geometrical and mechanical imperfections, ii) Interfacial non-linearity with deformable shear connectors of limited ductility, iii) Elasto-plastic material models for high performance steel with various degrees of strain hardening, iv) Advanced reinforced concrete material models with normal to high strength concrete, v) Full deformation ranges against different failure criteria: steel stresses, concrete strains, overall deflections, slippages of shear connectors, vi) Effect of propping (or shoring) during construction.;Significance of the research work: This research work provides detailed understanding on the structural behaviour of long span simply supported and continuous composite beams with practical configurations. These practical constructional features include i) shear connectors with different load-slippage curves, ii) different construction methods, iii) different levels of strain hardening, and iv) high performance materials with various combinations. These comprehensive numerical investigations are considered to be very helpful in understanding the realistic structural behaviour of composite beams, and providing extensive experience in numerical modelling as well as data analysis of composite beams with deformable shear connectors of various ductility. Moreover, detailed understanding on the structural behaviour of composite beams with normal to high strength materials is also provided, together with the proposed design equations utilizing an elasto-plastic stress distribution across the depths of the composite cross-sections. These proposed design equations are considered to be very helpful in developing modern analysis and design rules for practical design. Furthermore, advanced finite element models have been established successfully for composite beams with practical configurations and constructional features. Due to the high efficiency of the proposed finite element models, the computational resources for the execution of those models are found to be readily available in modern research offices. |
