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Steel tubular frames are often used to build a variety of structures because of their optimal mechanical properties and attractive forms. However, their joint fabrication involves a vast quantity of cutting and welding works, which induces high labour costs, material waste, and environmental pollution. The construction industry dominates the global...
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... build-up the 3D model of the joint, a parametric joint builder tool was developed (Fig. 6). The original structure consists of four different groups of joints with similar geometry (170 types of joint geometries in total). For this article, two representative versions are generated: a symmetric (S) and an asymmetric case (A) ( Fig. 7 a and ...
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... The main objective was to understand how the 3D printing stages can affect the mechanical properties of the connection. The selected case was the DS-R solution-symmetric with a volume fraction = 50% DS. The first three steps of the workflow include importing a tessellation file (STL), the orientation selection and the support generation (Fig. 26). The typical problems during the build-up of metal powder layers have been studied, such as residual stresses and distortions. Post-process treatments can largely eliminate the residual stresses formed during the process. The orientation assessment is essential to evaluate the feasibility of a specific part to be printed within the ...
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... Topology Optimisation was consolidated as a discipline forty to fifty years ago but experienced exponential growth in its research output only in the new millennium. Its most significant developments for the general optimisation of connections in structural engineering (Donofrio 2016; Li and Tsavdaridis 2021;Lange et al. 2020) and of specific joint types, such as nodes of tubular structures Kanyilmaz and Berto 2019;Kanyilmaz et al. 2020;Hassani et al. 2020;Huang et al. 2021) as well as on the most suitable AM techniques for fostering the TO of joints (Mishra et al. 2022;Bruggi et al. 2021;Laghi et al. 2022) were summarised and discussed in (Ribeiro et al. 2021) and (Ibhadode et al. 2023). A general conclusion drawn from this investigation is that these advancements are difficult to incorporate in the state-of-practice of design and detailing that comply with code requirements. ...
The application of Topology Optimisation (TO) to help in the manufacture of metallic components in highly technological industries has increased recently. To equally benefit from TO, the construction industry must address its specific issues, such as adherence to code requirements and challenges in using cutting-edge software packages in complex joints with non-linear behaviour. To assist in such a challenge, the current study offers a methodology proposal to synthesise code and structural behaviour requirements into geometrical constraints for the optimisation problem of laminar steel parts under compression while integrating Non-linear Finite Element Analyses (NLFEA) that ensure the safety of the solution. It has been found that, for a real case-study, the initial volume of a connection’s cover-plate can be decreased by up to 40% while maintaining the connection's original capacity and that a 30% volume decrease may be achieved while keeping the original plate capacity. In both cases, the plate’s ultimate deformation capacity was enhanced. Evidence has been found that Linear Elastic TO may not provide safe-sided solutions for parts with an intrinsic non-linear behaviour. With the attained volume reductions, less raw materials may be consumed, assembly and transportation will be facilitated, and the goals of the sector’s decarbonisation, energy intensity and sustainability will be favoured.
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... Additionally, the map delves into Cluster 03, focusing on optimization and artificial intelligence, clarifying the intersection between computational methods and advanced engineering principles. Similarly, Cluster 04 is dedicated to 3D printing and energy absorption, comprising thirteen (13) nodes with 27 cooccurrences, focusing on material composites [145][146][147], and structure [148], as well as metaheuristic approaches to engineering problems, showcasing the dynamic nature of research in these areas and hinting at future directions and potential breakthroughs. Moreover, Cluster 06 explores the mechanical properties of biomimetic materials, such as compressive strength and toughness, alongside numerical simulations elucidating the behaviour of biomaterials under varying conditions. ...
This paper presents a bibliometrics analysis aimed at discerning global trends in research on 'biomimetics', 'biomimicry', 'bionics', and 'bio-inspired' concepts within civil engineering, using the Scopus database. This database facilitates the assessment of interrelationships and impacts of these concepts within the civil engineering domain. The findings demonstrate a consistent growth in publications related to these areas, indicative of increasing interest and impact within the civil engineering community. Influential authors and institutions have emerged, making significant contributions to the field. The United States, Germany, and the United Kingdom are recognised as leaders in research on these concepts in civil engineering. Notably, emerging countries such as China and India have also made considerable contributions. The integration of design principles inspired by nature into civil engineering holds the potential to drive sustainable and innovative solutions for various engineering challenges. The conducted bibliometrics analysis grants perspective on the current state of scientific research on biomimetics, biomimicry, bionics, and bio-inspired concepts in the civil engineering domain, offering data to predict the evolution of each concept in the coming years. Based on the findings of this research, 'biomimetics' replicates biological substances, 'biomimicry' directly imitates designs, and 'bionics' mimics biological functions, while 'bio-inspired' concepts offer innovative ideas beyond direct imitation. Each term incorporates distinct strategies, applications, and historical contexts, shaping innovation across the field of civil engineering.
... With the development of metal AM technologies, which is envisioned as one of the leading technology for construction transformation [14], new possibilities has been introduced to realise such efficient and optimised structures for real-world applications. Given the inherent synergy between TO and AM, research has also been focused on further development of TO for AM to tailor it for large-scale applications [15], to take into account AM deposition direction [16; 17], to consider thermal history during AM for adjusting material properties [18], and to develop new structural design concepts [19][20][21][22][23]. ...
Wire arc additive manufacturing (WAAM) enables the manufacturing of efficient and lightweight structural elements in which material can be utilised wherever needed in an optimised shape, in contrast to standard prismatic profiles used in construction. However, the specific energy consumption (SEC) of WAAM is higher than that of conventional manufacturing (CM) techniques (i.e., hot-rolling) for standard profiles. Therefore, it is an open question whether the material savings through computational design realised through WAAM is environmentally beneficial or not. This systematic study aims to provide a better understanding of the environmental impact of hybrid manufacturing, which is defined as the combination of WAAM and CM rather than using any of them alone. Topology optimisation (TO) is used to design a series of beams with an identical performance (i.e., stiffness) but with a reduced material consumption depending on the hybrid ratio. The environmental impact of the designs has been used to determine when and how hybridisation can become advantageous. The results show that although the optimal proportions of WAAM and CM are dependent on their relative SEC, the hybrid solutions have always been environmentally superior compared to that of WAAM or CM alone for the realistic SEC values. The results showed that the hybrid beams can exhibit up to a 60% reduction in environmental impact compared to that of CM.
... On the basis of the rising steel structure requirements for resource efficiency, simplified assembly and optimised design can find a beneficial tool in metal additive manufacturing (MAM) [2][3][4] for the production of structural nodes [5][6][7][8][9][10][11][12]. By employing optimised additively manufactured nodes to join traditionally manufactured large regularshaped profiles, MAM can find a favourable and sustainable use in the construction sector (Fig. 1a) [8,13]. Indeed, this solution exploits the advantages and meets the limits of both traditional and additive manufacturing. ...
... Among the most relevant contributions in the field of TO in metallic connections, one can refer to the work of Wang et al. [76] in tree structures, as well as to the developments of Kanyilmaz et al. [34,35] in the optimisation of joints between tubular elements, and of Hassani et al. [22] in spherical nodes of spatial structures. ...
Topology optimisation (TO) is increasingly used to assist metallic parts manufacturing in automotive, aerospace, and biomedical sectors. A similar trend is observed in civil engineering structures, particularly in steel construction joints representing crucial steelwork components. Yet, the widespread adoption of TO to steel members in structural engineering has been hampered by difficulties complying with code requirements and challenges in utilising cutting-edge software in real, heterogeneous, and complex cases. To fill this research gap, a methodology is developed in the current study to implement the requirements of Eurocode 3 in the TO process. Nonlinear Finite Element Analyses (NLFEA) are performed on the web cover-plates of a well-known bolted splice connection between segments of a steel beam to validate the code-compliant methodology. Results show that it is possible to reduce up to 87.5% of the plate initial volume while keeping the connection original capacity. Also, it has been found that the initial volume can be reduced up 20% without affecting the original plate capacity, and up to 60% while ensuring that the ultimate plastic displacement is larger than that of the original plate. Based on extensive buckling analyses, critical loads exceed ultimate loads from 9.3 to 12.4 folds, thus ensuring excellent stability performance. The results of this study demonstrate that validation with NLFEA is a crucial step for achieving actual code-compliant optimised steel joints, and that the linear elastic TO could not satisfy the safety requirements. Moreover, encouraging findings regarding stability and ductility of (extremely) optimised parts suggest the adequacy of TO for designing steel connections. The volume of topologically optimised solutions significantly decreased, contributing to the decarbonisation targets for steel construction.
... The usage of TO techniques is facilitating the growth of Additive Manufacturing (AM), which can create manufacturable structures from TO results [40]. Moreover, the potential for weight reduction in connections is substantial [41], as is the prospect of developing new connection concepts [42][43][44][45][46]. ...
In this work, Non-penalisation Smooth-Edged Material Distribution for Optimising Topology (np-SEMDOT) algorithm was developed as an alternative to well-established Topology Optimisation (TO) methods based on the solid/void approach. Its novelty lies in its smoother edges and enhanced manufacturability, but it requires validation in a real case study rather than using simplified benchmark problems. To such an end, a Sheikh-Ibrahim steel girder joint's tension cover plate was optimised with np-SEMDOT, following a methodology designed to ensure compliance with the European design standards. The optimisation was assessed with Physical Nonlinear Finite Element Analyses (PhNLFEA), after recent findings that topologically optimised steel construction joint parts were not accurately modelled with linear analyses to ensure the required highly nonlinear ultimate behaviour. The results prove, on the one hand, that the quality of np-SEMDOT solutions strongly depends on the chosen optimisation parameters, and on the other hand, that the optimal np-SEMDOT solution can equalise the ultimate capacity and can slightly outperform the ultimate displacement of a benchmarking solution using a Solid Isotropic Material with Penalisation (SIMP)-based approach. It can be concluded that np-SEMDOT does not fall short of the prevalent methods. These findings highlight the novelty in this work by validating the use of np-SEMDOT for professional applications.
... On the basis of the rising steel structure requirements for resource efficiency, simplified assembly and optimised design can find a beneficial tool in metal additive manufacturing (MAM) [2][3][4] for the production of structural nodes [5][6][7][8][9][10][11][12]. By employing optimised additively manufactured nodes to join traditionally manufactured large regularshaped profiles, MAM can find a favourable and sustainable use in the construction sector (Fig. 1a) [8,13]. Indeed, this solution exploits the advantages and meets the limits of both traditional and additive manufacturing. ...
The demand for free-form steel structures having improved performances, reducing labour and resource usage is increasing in the construction sector. Structural nodes are some of the most critical regions for steel structures characterised often by large dimensions. These nodes can exploit the geometrical freedom of metal additive manufacturing (MAM) processes. Laser powder bed fusion (LPBF) is arguably the most developed MAM process, which has limitations regarding the size of the parts to be produced. A way to overcome the size limits of LPBF for producing structural nodes while still exploiting its geometrical capacity is producing hybrid components by welding them to traditionally manufactured beams. Such hybrid joints would constitute a complex system from a mechanical design perspective requiring a systematic analysis in order to be certified for structural use. Accordingly, this work studies the mechanical behaviour of hybrid steel components generated by welding LPBF plates and quarto plates made of AISI 316L stainless steel. The work was guided by a case study based on a large steel node, which helped defining the requirements to fill the gap of the international standards. The mechanical characterisation of LPBF-produced plates and quarto plates, as well as the welded hybrid components revealed a maximum of 10% difference between the properties of the differently manufactured plates. Through the digital image correlation (DIC) analyses, the anisotropic deformation behaviour along the LPBF, weld seam, and quarto plate regions have been identified, and the properties after welding did not show relevant modifications. The tests allowed to define that the failure behaviour is mainly governed by interlayer bounds, and a 0.9 safety reduction parameter for considering the reduction of ductility induced by arc welding to LPBF. Finally, design and production suggestions have been provided for a correct evaluation of gross and effective sections of the designed nodes.
... Hollow sections have outstanding mechanical and aesthetical properties because of their symmetric geometry. Moreover, a hollow section has a lighter weight with equal structural resistance, resulting in a lighter construction (Kanyilmaz et al. 2021b), and requires a smaller volume of fire protection material than equivalent double T sections (Bursi et al. 2008). The laser cutting technology (LCT) joint fabrication involves the machine laser cutting of the structural element's edges and full penetration welding of connecting details (Castiglioni et al. 2016). ...
... From a practical point of view, laser cutting machines are prone to be used for round tubes with diameters ranging from 10 to 508 mm, with wall thickness until 20 mm and lengths until 14 m (Kanyilmaz et al. 2021b). Although laser cutting machines involve high costs, this technology permits the reduction of the overall lifecycle costs (i.e., manufacturing costs and delay costs). ...
Directly welded truss girder joints result in high-stress development on the tube wall, which leads to increased chord thicknesses, requires extra welding, and presents detailing difficulties. Laser cutting technology (LCT) allows us to make precise cuts and pass through the truss members, welding the connection on the two sides. This can reduce geometrical imperfections, and, as a result, it increases joint strength. This paper presents truss girder joints developed with LCT that can develop higher resistance to static gravity loads with respect to conventional connections thanks to the pass-through solution. An extensive experimental campaign (31 specimens) has been carried out involving the monotonic gravity loading of several truss specimens to simulate their in-service conditions. Different truss typologies are tested (Warren and Pratt) using circular and square hollow section profiles, at different scales (full-scale and small-scale). The results showed that Warren-type structures with LCT connection solutions had a 20% higher strength with respect to the equivalent structures with directly welded joints. Furthermore, the correlation between the different failure modes and joint parameters (e.g., angles and distance between brace members) has been discussed.
... In Table S1 in the supplementary file, 103 case studies on the application of TO and MAM in major industries drawn from several research efforts are presented. 29 of these case studies are categorised under aerospace (Süß et al. 2016;Seabra et al. 2016;Magerramova, Vasilyev, and Bittredge et al. 2022;Liu et al. 2021b;Seebach et al. 2020;Seebach et al. 2017;Dai et al. 2018;Liu, Jiang, and Lin 2020b;Al-Tamimi et al. 2017;Al-Tamimi, Peach, and Bartolo 2018;Wang et al. 2020a;Lin et al. 2021), 25 under automotive (Dalpadulo, Pini, and Leali 2020a;Walton and Moztarzadeh 2017;Vaverka, Koutny, and Palousek 2019;Reddy et al. 2016b;Bikas et al. 2016a;Großmann et al. 2020;Tyflopoulos, Lien, and Steinert 2021;Bici, Broggiato, and Campana 2016;Junk, Fleig, and Fink 2017;Barbieri et al. 2017;Barbieri et al. 2018;Barreiro et al. 2019;Hunar et al. 2020;Marchesi et al. 2015;Mantovani, Campo, and Ferrari 2020;Mesicek et al. 2021;Ahn et al. 2021;Bujny et al. 2021;Cecchel 2020;DeBoer et al. 2021;Dalpadulo, Pini, and Leali 2021c;Dalpadulo, Pini, and Leali 2021a;Dalpadulo, Pini, and Leali 2021b;Abdi, Ashcroft, and Wildman 2018), and 23 under others (Ngim, Liu, and Soar 2007;Herbin, Grzesiak, and Krolikowski 2017;Lynch et al. 2013;Steuben et al. 2017;Ye et al. 2021;McEwen et al. 2018;Dalpadulo et al. 2020b;Nourbakhsh et al. 2016;Xiao et al. 2018;Xu et al. 2017;Pilagatti et al. 2021;See et al. 2022;Ueno et al. 2021;Alexandersen, Sigmund, and Aage 2016;Alexandersen et al. 2018;Dede, Joshi, and Zhou 2015;Hayes and Whiting 2021;Kanyilmaz et al. 2020;Mirzendehdel, Behandish, and Nelaturi 2022;Yan et al. 2022;Raz, Chval, and Stepanek 2022;Schuh et al. 2020;Ho et al. 2021). The major areas identified in these studies are the adopted TO model, optimisation objective, material, and MAM process. ...
Metal additive manufacturing is gaining immense research attention. Some of these research efforts are associated with physics, statistical, or artificial intelligence-driven process modelling and optimisation, structure–property characterisation, structural design optimisation, or equipment enhancements for cost reduction and faster throughputs. In this review, the focus is drawn on the utilisation of topology optimisation for structural design in metal additive manufacturing. First, the symbiotic relationship between topology optimisation and metal additive manufacturing in aerospace, medical, automotive, and other industries is investigated. Second, support structure design by topology optimisation for thermal-based powder-bed processes is discussed. Third, the introduction of capabilities to limit manufacturing constraints and generate porous features in topology optimisation is examined. Fourth, emerging efforts to adopt artificial intelligence models are examined. Finally, some open-source and commercial software with capabilities for topology optimisation and metal additive manufacturing are explored. This study considers the challenges faced while providing perceptions on future research directions.
... On the basis of the rising steel structure requirements for resource efficiency, simplified assembly and optimised design can find a beneficial tool in metal additive manufacturing (MAM) [2][3][4] for the production of structural nodes [5][6][7][8][9][10][11][12]. By employing optimised additively manufactured nodes to join traditionally manufactured large regularshaped profiles, MAM can find a favourable and sustainable use in the construction sector (Fig. 1a) [8,13]. Indeed, this solution exploits the advantages and meets the limits of both traditional and additive manufacturing. ...
