Search Results (8)

Significant inelastic deformations induced in structural systems lead to structures possibly possessing some degree of permanent lateral deformation following major seismic events. These permanent deformations have led to considerable research being conducted over the past 20 years into developing structural systems that exhibit self-centring behaviour. For a structural system such as the concentrically braced frame (CBF), for which the dissipating mechanism is the tensile yielding and compressive buckling of the diagonal steel tubular members, these residual deformations present a problem when considering the structure’s overall resilience to the seismic loading both during and after an event. This paper describes the numerical modelling of a novel self-centring, concentrically braced frame (SC-CBF) system that combines a conventional CBF with a self-centring arrangement to produce a structure that possesses the desirable lateral load-resisting capacity of the CBF but which also re-centres when subjected to many cycles of large inelastic brace deformation. First, an experimental test programme for the SC-CBF is briefly described, followed by a numerical model to capture the SC-CBF’s characteristics during cyclic loading. This numerical model is validated using the experimental test data, showing that the experimental and numerical simulation data match rather well. This development presents a platform upon which further research through experimental testing and numerical simulation can be conducted. The proposed SC-CBF system can then be developed into a viable lateral load-resisting system that will provide a more resilient system than the current conventional CBF. Full article

Education for sustainable development (ESD) is a growing research field, particularly over the last decade. Measuring the level of ESD that is currently embedded in curricula is useful for planning the further implementation of sustainability-related teaching. The Sustainable Development Goals (SDGs) are a useful benchmark for sustainability topics and so this paper follows a methodology in which a keyword scanning tool was created to quantify the level of SDG coverage within a list of learning outcomes for a module. The aim of the research is to further develop this methodology and compare the results from the keyword tool with results from a survey of the academic staff who deliver the modules. SDG-related keyword lists were collected from multiple sources for a meta-analysis, examining the performance of various lists. These lists were then compiled into one list of over 12,000 SDG keywords and a team of reviewers conducted a critical analysis on the relevancy of the context in which the keywords were found when scanned. This process reduced the list to 222 “crucial keywords” and gave the keywords a relevancy label based on the STARS definitions, the sustainability tracking assessment and rating system. Finally, ChatGPT was also investigated as a method of enriching the critically analysed list with contextually relevant synonyms. A survey was carried out within the College of Science and Engineering at the University of Galway. It asked staff to rate the level of SDG coverage within their own modules, in their own opinion. This gave results which could be compared with the keyword scanning tool. The findings show success in improving the accuracy of the SDG keywords. ChatGPT added synonyms to the crucial keywords identified and this list was the most accurate out of all keyword lists used in the study. Using these keywords and the modules that staff rated in the survey, a correlation was found in the SDG trend. Full article

Over the last two decades, the tidal energy industry has laid the groundwork for creating commercially viable tidal power generation projects to strengthen sustainable energy policies around the world. At the end of 2021, the cumulative installation of tidal stream technology that has been deployed in Europe reached 30.2 MW, where the majority of the installations are by small and medium-sized companies. Due to a growing demand among investors related to the global tidal energy industry, the reliability and safety of operational-stage tidal energy systems’ components are becoming increasingly important. In this context, companies, universities and research institutes are focusing on conducting large- and small-scale tests of tidal turbine elements to validate their projected design life, and major attention is being given to assessing the structural integrity of turbine blades. This review paper focuses on structural tests that have been reported for axial flow tidal turbine blades manufactured using composite materials around the world, highlighting the testing standards, equipment and instrumentation required. Overall, this review article discusses the state of the art in the structural testing of tidal turbine blades. In addition, it highlights the global concerns and research gaps to ensure the long-term sustainability of axial flow tidal turbine blades. In addition, the information contained in this article will be useful for formulating a smooth and reliable mechanism to enhance the evaluation process of the structural properties of tidal turbine blades in the future. Full article

Currently, wind energy, a reliable, affordable, and clean energy source, contributes to 16% of Europe’s electricity. A typical modern wind turbine design lifespan is 20 years. In European Union countries, the number of wind turbines reaching 20 years or older will become significant beyond 2025. This research study presents a methodology aiming to upgrade rotor blades for existing wind turbines to extend the turbine life. This methodology employs blade element momentum theory, finite element analysis, genetic algorithm, and direct screen methods to optimise the blade external geometry and structural design, with the main objective to increase the blade power capture efficiency and enhance its structural performance. Meanwhile, the compatibility between the blade and the existing rotor of the wind turbine is considered during the optimisation. By applying this methodology to a 225 kW wind turbine, an optimal blade, which is compatible with the turbine hub, is proposed with the assistance of physical testing data. The optimised blade, which benefits from high-performance carbon-fibre composite material and layup optimisation, has a reduced tip deflection and self-weight of 48% and 31%, respectively, resulting in a significant reduction in resources, while improving its structural performance. In addition, for the optimised blade, there is an improvement in the power production of approximately 10.5% at a wind speed of 11 m/s, which results in an increase of over 4.2% in average annual power production compared to the existing turbine, without changing the blade length. Furthermore, an advanced aero-elastic-based simulation is conducted to ensure the changes made to the blade can guarantee an operation life of at least 20 years, which is equivalent to that of the reference blade. Full article

This paper presents the positive experience of facilitating over 300 community-engaged engineering projects at an Irish higher-education institution. The projects are framed by a research orientation, a commitment to civic engagement, and building university–community partnerships, city–university partnerships, and partnerships with other official agencies, so that community users can provide real learning problems and contexts for students and researchers and benefit from the results. The paper highlights how well the outlined approach fits with the ideas of engaged scholarship and civic professionalism, and facilitates sustainable development. Students recognise the long-term value of engaging with community partners, understanding their future role in the community as engineers, reinforcing the idea that their work can respond directly to real needs in the community, while promoting the sustainability agenda at the same time. The approach presented in this study will not only enable the development of future models for embedding sustainability in engineering programs, but will also equip future engineers with transferable skills to ensure that sustainable development goes beyond university courses and is practiced every day. Full article

Quantifying the wider benefits of energy efficient building retrofits is crucial to incentivise householder retrofit investments. This research recognises the value of key performance indicators (KPIs) for assessing and demonstrating retrofitting benefits and provides an assessment of KPIs for evaluating retrofits. An integrated framework for evaluating retrofits using a set of economic, social, and environmental KPIs is proposed. This KPI framework is then applied in a pre- and post-retrofit assessment of five case study dwellings located in Ireland, revealing its usefulness in demonstrating the wider benefits of retrofitting to householders, with a view to driving retrofit investment. Three of these case study dwellings had state-of-the-art retrofit technologies installed as part of the works, including heat pumps and solar PV systems. In addition to demonstrating the wider benefits of retrofitting, the framework allowed for the identification of potential causes for differences in performance of these technologies across households, as well as patterns of underperformance. Such insights are useful for the future design of these technologies and retrofit packages, as well as policy measures, which support householders in the adoption and use of these measures. The results demonstrate that householders experience various benefits from retrofitting. Showcasing the different benefits that householders receive from retrofitting, and their satisfaction with the retrofit works, can serve to de-risk retrofit investments, and inspire others to seek similar benefits through retrofitting. Applying the developed framework to a larger, comparable sample size, can distinguish the retrofit packages, which perform best across the KPIs and various household profiles. Furthermore, the application of the developed framework can serve as an evidence base for retrofit designers, contractors, and policy makers in the design of retrofit packages and policy measures that will maximise the benefit for householders. Full article

As the world shifts to using renewable sources of energy, wind energy has been established as one of the leading forms of renewable energy. As the requirement for wind energy increases, so too does the size of the turbines themselves, where the latest turbines are 10 MW with a turbine diameter in excess of 190 m. The design and manufacture of the blades for these turbines will be critical if they are to last for the design life, where the accuracy of the numerical models used in the design process is paramount. Therefore, in this paper, three independent numerical models have been created using three available finite element method packages—ABAQUS, ANSYS, and CalculiX—and the results were compiled. Following this, the accuracy of the models has been evaluated and validated against the results from an experimental testing campaign. In order to complete the study, a 13 m full-scale wind turbine blade has been used, which has been subjected to static testing in both the edgewise and flapwise directions. The results from this testing campaign, along with the blade mass and natural frequencies, have been compared to the results from the independent numerical models. The differences in the models, along with other sources of error, have been discussed, which includes recommendations on the development of accurate numerical models. Full article

Wave characteristic assessments of wave energy test sites provide a greater understanding of prevailing wave conditions and are therefore extremely important to both wave energy test site operators and clients as they can inform wave energy converter design, optimisation, deployment, operation and maintenance. This research presents an assessment of the wave resource at the Atlantic Marine Energy Test Site (AMETS) on the west coast of Ireland based on 12-years of modelled data from January 2004 to December 2015. The primary aim is to provide an assessment of annual and seasonal wave characteristics and resource variability at the two deployment berths which comprise the site. A nested model has been developed using Simulating WAves Nearshore (SWAN) to replicate wave propagations from regional to local scale with a 0.05° resolution model covering the northeast Atlantic and a 0.0027° resolution model covering AMETS. The coarse and fine models have been extensively validated against available measured data within Irish waters. 12-year model outputs from the high resolution model were analysed to determine mean and maximum conditions and operational, high and extreme event conditions for significant wave height, energy period and power. Annual and seasonal analyses are presented. The 12-year annual mean P were 68 kW/m at Berth A (BA) and 57 kW/m at Berth B (BB). The resource shows strong seasonal and annual variations and the winter mean power levels were found to be strongly correlated with the North Atlantic Oscillation (NAO). Full article