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Abstract

This thesis describes the development of an inelastic stability analysis for restrained pin-ended steel beam-columns having an axial load, biaxial end moments and lateral loads in X and Y directions along the length. The lateral loads may be a combination of several distributed and concentrated loads. The beam-column cross-sections are uniform along the length, and may be doubly or singly symmetric. Ultimate loads can be obtained by increasing some or all components of the loads. The analysis can be made with or without considering residual stresses and torsion effects. The analysis essentially consists of obtaining eguilibrium shape corresponding to increasing values of the principal variables up to the peak of the applied load versus deflection curves. The Newton-Raphson method is employed for the iteration in the analysis.Solutions of the integration of stress resultants are obtained with the Gaussian guadrature formulae.

Experiments of eight full-scale steel beam-columns loaded uniaxially and biaxially are reported and used to check the validity of the analytical method. The slenderness ratios of the beam-columns tested were 78 and 117. These values were chosen to cover the intermediate and the slender beam-columns. The discrepancy between the observed and calculated strength remains an average of 93% with a standard deviation of 8%.

The theoretical model was applied to generate interaction curves for pin-ended steel beam-columns with concentrated and linearly distributed loads. The results were compared with BS 5400:Part3. Further, the theory was also used to study the effects of residual stresses and torsion on the calculated collapse loads. It was found that residual stresses could reduce the beam-column strenqth by up to 15%, whereas reduction as much as 35% was found due to the torsional effects on beam-columns with slenderness ratio 60.

Publication Type:	Thesis (Doctoral)
Subjects:	T Technology > T Technology (General) T Technology > TA Engineering (General). Civil engineering (General)
Departments:	School of Science & Technology > Engineering School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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