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Title: Application of layout optimization to the design of bracing in buildings
Author: Lu, Hongjia
ISNI:       0000 0004 7226 4574
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2017
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In civil engineering, techniques for the design and construction of tall buildings have expanded rapidly in recent decades. However, developments in layout/topology optimization techniques which can be applied to such structures have not kept pace. Consequently, currently the layout of structural members in buildings usually relies primarily on the engineer's experience. On the other hand, numerical layout optimization techniques appear potentially to be very suitable for building layout design, and yet have not been used in practical building design. Therefore, this thesis investigates the application of layout optimization in building layout / topology design, and especially focusses on the design of bracing layout. The bracing structure (or lateral stability structure) is an essential component of any building that is used to provide stability against wind loads. Usually, the acting positions of the lateral loads are dependent on the building shape. However, this point has not been the subject of investigation in previous studies of bracing layout optimization. Therefore, two current numerical means of treating design dependent loads (i.e. transmissible loads) are investigated and compared in this thesis. The difference between these two means are identified and proved through the use of mathematical and numerical approaches. Additionally, during the investigation it has been found that taking advantage of pre-existing rigid bars in the optimization may lead to more efficient and simple structures. Therefore, in the following bracing design case studies, various assumptions about pre-existing bars are made. The case studies involving bracing design comprise three main elements, covering a range of assumptions as follows: (1) Optimal bracing for pre-existing beam-column frames which are required to resist lateral loads are identified. (2): Optimal frames which are required to resist both vertical and lateral load cases are identified. (3): Optimal frames which are required to resist lateral load cases are identified with the assumption of pre-existing beams. This allows the bracing structure and external building envelope to be simultaneously identified. It has been found in this study that cases with different assumptions lead to very different solutions, which may be selected for use based on the real situation. Additionally, some supplementary findings related to analytical optimal solutions and the use of the superposition approach in multiple load cases are outlined; details can be found in the main chapters.
Supervisor: Matthew, Gilbert ; Andrew, Tyas Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available