Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582474
Title: Cyclic behaviour of hollow and concrete-filled circular hollow section braces
Author: Sheehan, Therese
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2013
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Abstract:
Presented in this thesis is an investigation on the response of hot-finished and cold formed, hollow and concrete-filled circular hollow section braces in earthquakeresisting concentrically braced frames. The role of these braces is to act as structural ‘fuses’ in the frame, dissipating the seismic energy by undergoing plastic deformations. Circular hollow sections offer aesthetic and structural advantages over conventional rectangular hollow sections owing to the uniformity of the section geometry. Distinct behaviour is observed between cold formed and hot-finished tubes, since the cold formed sections retain a higher degree of residual stresses from manufacturing. Braces subjected to cyclic loading fail after the occurrences of global and local buckling, but the performance can be enhanced by employing concrete infill. The concrete-filled steel tube is an optimum combination of the two materials, resulting in an efficient, economic and practical structural member. Experiments were performed in which cyclic axial loading was applied to hollow and composite braces of each section type. Hot-finished specimens exhibited superior ductility to cold formed members. Concrete infill enhanced the tensile resistance for members of all lengths, the compressive resistance of shorter members and the number of cycles to failure. Finite element models were subsequently developed with ABAQUS® software, using the inbuilt nonlinear isotropic/kinematic hardening model and the damaged plasticity model to define the steel and concrete characteristics. Reliable simulations were achieved for the hollow braces but further work is required for the composite braces. Both local and global slenderness values influenced the specimen response. Expressions were proposed to predict the displacement ductility and energy dissipation capability of hollow braces in terms of these parameters. The findings suggest that distinct guidelines could be developed for introduction into Eurocode 8 for each steel section type, and that the benefits of concrete infill could be taken into account in dissipative design.
Supervisor: Not available Sponsor: Tata Steel
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.582474  DOI: Not available
Keywords: TA Engineering (General). Civil engineering (General)
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