Application of structural topology optimisation in aluminium cross-sectional design

Aluminium is lightweight and corrosion-resistant; however, its low Young's Modulus predisposes the need for better material distribution across its section to increase stiffness. This paper studies a holistic design optimisation approach with the power of structural topology optimisation aiming to develop novel structural aluminium beam and column profiles. The optimisation methodology includes forty standard loading combinations while the optimisation results were combined through an X-ray overlay technique. This design optimisation approach is referred here to as the Sectional Optimisation Method (SOM). SOM is supported by engineering intuition as well as the collaboration of 2D and 3D approaches with a focus on post-processing and manufacturability through a morphogenesis process. Ten optimised cross-sectional profiles for beams and columns are presented. The shape of one of the best performing optimised sections was simplified by providing cross-section elements with a uniform thickness and using curved elements of constant radius. A second level heuristic shape optimisation was done by creating new section shapes based on the original optimised design. The paper also carries out stub column tests using finite element analysis (FEA) to determine the loacl buckling behaviour of the above-optimised aluminium profiles under compression and to investigate the effectiveness of using the existing classification methods according to codified provisions of Eurocode 9. The herein presented work aims to integrate topology optimisation aspects in cross-sectional design of aluminium alloy element building applications, providing thus a new concept in design procedures of lightweight aluminium structures

Topology optimisation of lattice telecommunication tower and performance-based design considering wind and ice loads

With increasing demand of infrastructure to support power transmission and telecommunication systems, the need of erecting more towers has also been rising significantly. For many years, these towers were designed by using a conservative approach and the opportunities lying in the design optimisation of the towers were not leveraged. This paper presents the application of structural topology optimisation to lattice self-supported telecommunication towers in developing an improved solution in terms of weight-to-stiffness ratio. 2D and 3D topology optimisation studies were performed with highly optimised bracing systems reducing the amount of steel material used, thus its carbon footprint. The new exoskeleton structure is representing a lattice tower composed of ‘high-waisted’ bracing type and elliptical hollow sections (EHS). Comparative modal analyses demonstrated the structural performance of the optimised tower models. In addition, a research-led design was carried out for optimising the geometric cross-sectional properties of the optimised lattice tower subjected to quasi-static analysis followed by regression analysis. The cross-sectional parameters were progressively changed; explicitly the diameter and thickness of the members. The performance-based analysis and design of a topologically optimised lattice tower present alternatives to onerous approaches such as wind tunnel testing or finite element modelling. The results were further analysed to understand their viability in different loading design cases and the effect of cross-sections. Conclusions highlighted the benefits gained by introducing the structural topology optimisation process in the design of slender support structures

Novel Morphologies of Aluminium Cross-Sections through Structural Topology Optimization Techniques

In the last decades, the deployment of aluminium and its alloys in civil engineering fields has been increased significantly, due to the material’s special features accompanied by supportive technological and industrial development. However, the extent of aluminium structural applications in building activities is still rather limited and barriers related to strength and stability issues prevent its wider use. In the context of the extrusion characteristic, appropriate design in aluminium cross-sections can overcome inherent deficiencies, such as the material’s low elastic modulus. This paper investigates a new breed of cross-sectional design for aluminium members employing pioneering structural topology optimisation techniques. Topology optimisation problems utilise the firmest mathematical basis, to account for improved weight-to-stiffness ratio and perceived aesthetic appeal of specific structural forms. The current study investigates the application of structural topology optimisation to the design of aluminium beam and column cross-sections. Through a combination of 2D and 3D approaches, with a focus on post-processing and manufacturability, ten unique cross-sectional profiles are proposed. Additionally, the variation of cross-section along the member is also investigated in order to identify correlation between 2D and 3D topology optimisation results. Conclusions attempt to highlight the advantageous characteristics of aluminium use as well as the potential benefits to the more widespread implementation of topology optimization within the utilization of aluminium in civil/structural engineering