LIGHTSTEEL: New Generation of Lightweight Steel Elements for Sustainable Resilient Construction
Lead Research Organisation:
University of Sheffield
Department Name: Civil and Structural Engineering
Abstract
Modern society is challenged by economic and environmental issues such as climate change, requiring engineers to deModern society is challenged by economic and environmental issues such as climate change, requiring engineers to develop more efficient and sustainable construction solutions. The urbanisation and rapid population growth in earthquake-prone regions have also increased societal exposure to seismic related hazards and the urgent need for more resilient structural systems. Cold-formed steel (CFS) structures can offer a cost-effective and sustainable alternative to traditional construction systems, and are being increasingly adopted in modern construction due to their lightweight, rapid construction and full recyclability. However, typical CFS structures have low buckling resistance and ductility, which limits their practical application especially in seismic regions and tall buildings.
This research project aims to develop a novel CFS structural built-up system with high structural performance for rapid construction of multi-storey buildings in seismic regions. The new system benefits from high-performance CFS built-up elements optimised under axial and flexural loading by taking into account their post-buckling behaviour. This will allow for adoption of this system in tall buildings, large open spaces and flexible architectural design. Such innovative structural solutions can reduce the required structural weight, and hence, the construction costs and embodied carbon by 30-50% compared to conventional steel constructions. An advanced design framework will be developed to obtain cost-effective structures with optimum structural performance under normal (gravity and wind) and extreme (strong earthquake) load conditions. This project bridges the knowledge gap by developing fundamental understanding, advanced optimisation tools and performance-based design guidelines so that the new high performance CFS structural system can be widely used in practice.
This research project aims to develop a novel CFS structural built-up system with high structural performance for rapid construction of multi-storey buildings in seismic regions. The new system benefits from high-performance CFS built-up elements optimised under axial and flexural loading by taking into account their post-buckling behaviour. This will allow for adoption of this system in tall buildings, large open spaces and flexible architectural design. Such innovative structural solutions can reduce the required structural weight, and hence, the construction costs and embodied carbon by 30-50% compared to conventional steel constructions. An advanced design framework will be developed to obtain cost-effective structures with optimum structural performance under normal (gravity and wind) and extreme (strong earthquake) load conditions. This project bridges the knowledge gap by developing fundamental understanding, advanced optimisation tools and performance-based design guidelines so that the new high performance CFS structural system can be widely used in practice.
Publications
Dar M
(2023)
Development of lightweight CFS composite built-up beams: Tests and flexural response
in Journal of Constructional Steel Research
Dar M.A.
(2023)
Web crippling instability response in CFS built-up open beams: Numerical study and design
in Proceedings of the Annual Stability Conference Structural Stability Research Council, SSRC 2023
| Description | The key outcomes of this multidisciplinary research can be summarised as: • The ratio of the distance between the flange and the screw in the web to the depth of the web (e/h) of screws, bearing length and thickness of the channel influence the web crippling strength in cold-formed steel (CFS) built-up beams composed of plain channel sections, both under interior two-flange (ITF) and exterior two-flange loading cases. • The effect of e/h is more dominant on the web crippling capacity when the bearing length is higher compared to when the same is lower. • The influence of e/h on the web crippling strength is higher in thinner sections compared to thicker ones. • The impact of bearing length on the web crippling strength is magnified in thicker sections compared to thinner ones. • A stepped rise in the web crippling strengths is noted with each incremental rise in the channel thickness. • Both North American Specification (AISI S100) and Eurocode (EN 1993-1-3) indicate discrepancies in predicting the web crippling strength in CFS built-up beams composed of plain channel sections. The AISI predictions are mostly unconservative while as the same by are overconservative. |
| Exploitation Route | The outcomes of this project can help structural designers and practitioners to design more cost-effective and resilient lightweight steel structures. The high-performance optimised cold-formed steel (CFS) structural members will enhance the competitiveness of the UK steel industry and manufacturing profitability by reducing costs and energy consumption, ensuring their competitive advantage and contributing to the growth of the UK economy and job creation. |
| Sectors | Construction |
| URL | https://sites.google.com/d/1yfLbLSwIhSaC1qUjXw-vkEiM3kPbKpXH/p/1sME3Y3x-JU0omSCw0t9GziGXYzIeTgbk/edit |
| Description | The construction industry is a key driver of economic growth in the EU, with approximately 22% of total European construction output invested in new housing. However, the European steel industry faces significant challenges, particularly regarding the cost and availability of raw materials and energy, as well as competition from non-EU producers. In the long term, the outcomes of this research can provide the European construction sector with a competitive advantage and contribute to long-term economic growth by developing more efficient, lightweight steel structural systems. These innovations have the potential to reduce overall construction costs by at least 30% while enhancing strength and ductility-critical factors for multi-storey buildings, especially in seismic regions. Furthermore, the project aligns with the EU's global climate objectives, which target emissions reductions of 80-95% below 1990 levels by 2050. By developing sustainable structural systems that require less material, have a smaller carbon footprint, and offer full recyclability and reuse potential, this research contributes to more environmentally responsible construction practices. The project also enhances structural resilience, helping the EU develop buildings and infrastructure that are more robust against climate change, as well as natural and man-made hazards. The next generation of lightweight cold-formed steel (CFS) structural systems proposed in this project will lead to safer, more sustainable, and cost-effective construction, resulting in reduced waste, lower economic losses, and overall improvements in quality of life, health, and safety. The findings of this research are already being utilized by project collaborators Metsec and Hadley Group to develop more efficient, lightweight steel modular systems. These solutions offer clear advantages in terms of cost and sustainability compared to current industry practices. |
| First Year Of Impact | 2024 |
| Sector | Construction |
| Impact Types | Societal Economic |
| Description | New Generation of Sustainable Lightweight Cold-Formed Steel Structures |
| Amount | £12,000 (GBP) |
| Funding ID | IES\R2\232304 |
| Organisation | The Royal Society |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 09/2023 |
| End | 10/2025 |
| Title | Optimised CFS sections |
| Description | A new algorithm is developed to address the complex optimisation of cold-formed steel (CFS) beam, column, and beam-column elements based by taking into account the effects of geometric and material imperfections as well as manufacturing and construction constraints. The developed optimisation algorithm is used to produce a complete catalogue of optimum CFS sections for different applications, including more complex shapes such as folded flange sections. These optimised elements can be directly used in the practical design of resilient CFS structural systems. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | The developed optimisation methodology and practical optimum CFS members can lead to up to 40% less structural weight and construction cost. |
| Description | BW Industries |
| Organisation | BW Industries |
| Department | Research and Development |
| Country | United States |
| Sector | Private |
| PI Contribution | An advanced software is developed by my research team at The University of Sheffield to obtain more efficient cold-formed steel (CFS) beam and column sections with significantly higher ultimate capacity compared to existing standard sections. This has led to high-performance CFS dual wall-frame structural systems, which can be efficiently used in modular construction. |
| Collaborator Contribution | The BW Industries has provided access to valuable data and information on manufacturing process of CFS sections and construction constraints. They also provided the CFS sections required for the beam and column testing specimens. |
| Impact | - Advanced software to optimise complex cold-formed steel (CFS) sections based on Eurocode-3 by taking into account the manufacturing and construction constraints. - More efficient and cost-effective CFS beam and column sections. - More resilient CFS systems for new generation of modular structures. - Design oriented models to improve the performance of CFS moment resiting conections. - Experimental data base published as an open-access paper. |
| Start Year | 2024 |
| Description | Hadley Group |
| Organisation | Hadley Group |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | An advanced software has been developed by my research team at The University of Sheffield to obtain more efficient cold-formed steel (CFS) beam and column sections with significantly higher ultimate capacity compared to existing standard sections. Additionally, more efficient connection systems have also been developed to provide higher capacity and stiffness. These advancements have led to the creation of high-performance and low-cost CFS dual wall-frame structural systems, which can be efficiently used in modular construction. |
| Collaborator Contribution | The Hadley Group has provided access to valuable data and information on manufacturing process of CFS sections and construction constraints. They also provided the CFS sections required for the beam and column testing specimens. |
| Impact | - Development of advanced software for optimizing complex cold-formed steel (CFS) sections based on Eurocode-3 standards, considering manufacturing and construction constraints. - Enhancement of efficiency and cost-effectiveness in CFS beam and column sections. - Innovation in designing more resilient CFS semi-rigid connections tailored for modular structures. |
| Start Year | 2023 |
| Description | Imperial College London and Aberdeen |
| Organisation | Imperial College London |
| Department | Faculty of Engineering |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The research team at the University of Sheffield has contributed expertise in multi-criteria element-level optimization of cold-formed steel (CFS) elements and connections. Specifically, CFS stud elements have been optimized as beam-column elements to accommodate combined bending moment and shear effects at the joist ends, as well as midspan bending moment and deflection. Additionally, the team has provided training for post-doctoral researchers and PhD students from other institutions. |
| Collaborator Contribution | - The research team at University of Aberdeen provided numerical modelling on system development. - The research team at Imperial provided design method and physical testing. |
| Impact | -Advanced software designed to optimize complex cold-formed steel (CFS) sections according to Eurocode-3 standards, while considering manufacturing and construction constraints. The software is freely accessible to engineers. -Development of more efficient and cost-effective CFS beam-column sections specifically tailored for modular construction. |
| Start Year | 2023 |
| Description | Imperial College London and Aberdeen |
| Organisation | University of Aberdeen |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The research team at the University of Sheffield has contributed expertise in multi-criteria element-level optimization of cold-formed steel (CFS) elements and connections. Specifically, CFS stud elements have been optimized as beam-column elements to accommodate combined bending moment and shear effects at the joist ends, as well as midspan bending moment and deflection. Additionally, the team has provided training for post-doctoral researchers and PhD students from other institutions. |
| Collaborator Contribution | - The research team at University of Aberdeen provided numerical modelling on system development. - The research team at Imperial provided design method and physical testing. |
| Impact | -Advanced software designed to optimize complex cold-formed steel (CFS) sections according to Eurocode-3 standards, while considering manufacturing and construction constraints. The software is freely accessible to engineers. -Development of more efficient and cost-effective CFS beam-column sections specifically tailored for modular construction. |
| Start Year | 2023 |
| Description | Half day training workshop |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Professional Practitioners |
| Results and Impact | This half day seminar/presentations was organised by the PI at The University of Sheffield for UK Cold-Formed Steel (CFS) industry, consultants, contractors and engineers. Both undergraduate and post graduate students were also invited. The results of this meeting and the following open discussion led to several innovative and practical ideas to improve the resilient and efficiency of CFS forming process and final products. Some of these ideas will be developed further by applying for new UK and EU funding programmes. |
| Year(s) Of Engagement Activity | 2023 |
| Description | Invited Speaker at International Industry Events in Hong Kong |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Invited Speaker on "New Developments in Resilient and Sustainable Lightweight Steel Structures" at several academic and industry-led international events in Hong Kong: - ICE HKA and Hong Kong Metropolitan University joint event, May 2023 - The University of Hong Kong and American Society of Civil Engineers (ASCE) Greater China Section joint event, May 2023 - The Hong Kong Polytechnic University, May 2023 |
| Year(s) Of Engagement Activity | 2023 |
| Description | Invited speaker and round table discussions at UK universities |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Postgraduate students |
| Results and Impact | Invited speaker and round table debate on "New Generation of Adaptive Modular Lightweight Steel Structures" at: University of Aberdeen, UK, March 2025 University of Bristol, UK, July 2024 University of Birmingham, UK, November 2024 |
| Year(s) Of Engagement Activity | 2024,2025 |