The aim of this project is to develop a new type of composite beam that is light and has high constructability: This is achieved herein with the development of the PCFC beam which consists of a closed cold-formed steel section embedded in concrete. The motivation of the project comes from the availability of cold-formed steel to take any general form, a vital feature as it allows for optimum satisfaction of the composite supply and demand principle. The development of the beam requires several fundamental aspects to be investigated or/and formulated. The first of these is the study of the effect of the normal stresses and the frictional stresses induced as part of the longitudinal force transfer in the composite beam. This requires the derivation and solution of the differential equations describing the partial interaction of the composite beam. It has been found that the normal stresses do not have a significant effect on the elastic performance of the beam. However, the inclusion of the frictional stresses has been found to beneficially contribute to the longitudinal shear resistance of the beam. The complexity of the beam cross-section in terms of shape and materials means that the thesis has had to address calculation procedure developments. Initially, a general procedure is developed for which the key feature is the use of functions to describe the geometrical shape of the cross-section. This allows the procedure to cater for complex shapes as well as to divide the cross-section into its matrix representations, leading to an efficient computer programming coding. However, the discrete nature of the procedure limits it use to the calculation of the plastic moment capacity based on the rectangular stress block method. This limitation is removed in the enhanced version of the procedure where Fourier Series have been used to represent the flexural stress distribution as a single-rule function. This allows the use of more realistic material models and covers various stress stages without requiring iteration. The procedure and its extended version allows for the assessment of the PCFC beam, where it has been found that, although it is slightly less sufficient when considering some serviceability aspects, the beam performs better than the equivalent composite beams in the ultimate condition.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:486673 |
| Date | January 2007 |
| Creators | Yassin, Airil Yasreen Mohd |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/8054 |
Page generated in 0.0014 seconds