Design of a truss bridge for low cost using structural topology optimisation

Sutcliffe, Wayne (2016) Design of a truss bridge for low cost using structural topology optimisation. [USQ Project]

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This dissertation explores methods to reduce the cost of a steel truss bridge. It is focused on determining how effective Structural Topology Optimisation (STO) is in reducing costs in a real design problem and therefore gauging how practical STO is for use as a design tool.

Structural Topology Optimisation (STO) is the most general form of structural optimisation and uses rigorous computing methods to determine the optimum shape for a structure. STO is regularly used in automotive and aerospace but not is commonly employed in building structures.

The truss in this dissertation is a simply supported steel truss for an industrial plant with a 46 metre span. It has many potential alternative layouts and is an ideal test of the effectiveness of STO.

By applying STO to the concept design via an 88 line MATLAB program, a range of optimised geometry was produced. The STO procedure indicated a strong preference towards the warren truss as being the optimal shape for a bridge of this type.

The truss bridge was designed to determine member sizes, extract a bill of materials and apply live project cost rates for a range of geometry. The results showed an average reduction in cost for the truss bridge of approximately 3% by using the optimised geometry.

Other methods of structural optimisation such as changing to high strength steel, using hollow steel sections and increasing the truss depth in conjunction with the optimised geometry increased the estimated cost savings to approximately 9%. This larger reduction appeared to indicate a compounded effect from optimising several parameters of the design together.

It was identified from the results of this dissertation that having a combined model for STO, analysis and design and the ability to include cost rates and discrete member sizes into the optimisation to cater for their significant effect would likely increase the benefits gained by STO.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) Major Civil Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Ghabraie, Kazem; Banerjee, Sourish; English, Christian
Date Deposited: 24 Jul 2017 01:37
Last Modified: 24 Jul 2017 01:37
Uncontrolled Keywords: truss bridge; low cost; structural topology optimisation; MATLAB program
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090506 Structural Engineering
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400510 Structural engineering

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