Now showing items 1-20 of 2753

    • A bi-level multi-node optimal siting, sizing, and operation of multi energy system in an integrated energy network of electricity-gas-heat with peer-to-peer trading

      Rowe, Kirkland; Cooke, Kavian O.; Mokryani, Geev; Campean, I. Felician; Chambers, T. (2025-03-15)
      Multi-energy system (MES) technologies, such as energy hubs, link energy networks like electricity, natural gas, and district heating networks. This interlinking enhances the interdependence and interaction of the networks. While the interlinking of the networks to form an integrated energy system (IES) can improve flexibility, there are challenges in coordinating the IES. As a result, the integration and synchronisation of energy flows become challenging, affecting the coordination and optimisation of the overall energy system. This paper presents a novel bi-level optimisation model for the optimal siting, sizing, and operation of MES within an IES encompassing electricity, gas, and heat with peer-to-peer (P2P) trading and demand response. The research addresses the strategic placement and sizing of interconnected energy hubs with various distributed energy resources (DER), including renewable energy sources (RES) and power-to-gas (P2G) systems, to enhance the efficiency and sustainability of the IES. The upper-level optimisation aims to minimise the energy hubs' total investment and operating costs, while the lower-level focuses on reducing the cost of energy imports from upstream networks and implementing demand response programs to balance supply and demand, considering the constraints of the IES. By utilising the Karush-Kuhn-Tucker (KKT) optimality conditions and the big-M method, the bi-level problem is converted into a single-level Mixed-Integer Linear Programming (MILP) problem. The proposed model and methodology are validated through case studies on an integrated energy network based on the 16-bus 33 kV UK generic distribution system, a 20-node gas network and a 30-node heat network, demonstrating their effectiveness in the IES. The research demonstrates that coupled energy networks are viable for creating efficient and flexible IES. The strategic scheduling of energy hubs, equipped with generation equipment such as RES, storage, P2G and other conversion technologies operating within the IES with P2P energy trading, not only meets diverse energy demands but also enhances the sustainability and economic viability of the energy system.
    • Monitoring bone healing: Integrating RF sensing with AI

      Aldelemy, Ahmad; Adjei, E.; Siaw, P.O.; Al-Dulaimi, A.; Doychinov, Viktor; Ali, N.T.; Qahwaji, Rami; Buckley, John; Twigg, Peter C.; Abd-Alhameed, Raed (IEEE, 2025-01)
      This study presents the development of an advanced machine learning model based on a two-dimensional (2D) Radio Frequency (RF) sensing framework for refined monitoring of femoral bone fractures. Utilising MATLAB simulations, we created a comprehensive dataset enhanced with variations in bone diameter, muscle thickness, fat thickness, and hematoma size, augmented with multiple sensor configurations (two, four, six, and eight sensors). The model aims to provide a frequent, non-invasive assessment of the fracture healing process compared to conventional imaging methods. Our approach leverages data from six RF sensors, achieving a high overall accuracy of 99.2% in classifying different fracture stages, including “no fracture” and varying degrees of hematoma sizes. The findings indicate that increasing the number of sensors up to six significantly enhances detection accuracy and sensitivity across all fracture stages. However, the marginal improvement from six to eight sensors was not statistically significant, suggesting that a six-sensor configuration offers an optimal balance between performance and system complexity. The results demonstrate significant potential for this technology to revolutionise orthopaedic treatment and recovery management by offering continuous, real-time monitoring without radiation exposure. The proposed system enhances personalised patient care by integrating RF sensing with artificial intelligence, enabling timely interventions and more informed, data-driven treatment strategies. This research lays a robust foundation for future advancements, including three-dimensional modelling and clinical validations, toward the practical implementation of non-invasive fracture monitoring systems.
    • Optimal evolutionary framework-based activation function for image classification

      Parisi, Luca; Neagu, Ciprian Daniel; RaviChandran, N.; Ma, R.; Campean, Felician (2024-09)
      Typically, supervised Machine Learning (ML)-based image classifiers leverage algorithms derived from either Artificial Neural Networks (ANNs) or optimal separating hyperplane (OSH)-based algorithms. However, despite recent progress has been made to enhance ANNs’ classification performance via the Rectified Linear Unit (ReLU)-based activation functions (AFs), there is currently no AF that scales across and benefit both ANNs and OSH-based classifiers. Moreover, the lack of globally optimal AFs leads to a high variance in image classification-related results. Thus, this study seeks to overcome this limitation by implementing a next-generation evolutionary framework (‘ActiGen’) to generate a novel and more reliable AF, which can scale to two families of AFs for two classifiers. The proposed evolutionary knowledge-based framework leverages a Multi-Objective (MO) optimisation method based on Genetic Algorithms (GA), or ‘MOGA’, to improve the generalisation of such classifiers. This evolutionary framework and its generated AF are validated using nine open-access datasets: seven image-based datasets, consisting of 22,136 images in total, and two large (561 features for 10,929 instances, 124 features for 1,700 instances) tabular datasets. These diverse datasets include both binary and multi-class classification, such as images of breast masses, those acquired via cardiac computed tomography, photos of famous people from the Internet, images of handwritten digits and those drawn on a graphics tablet, human faces with different lighting, details, and expressions, smartphone-related data captured during various activities and postural transitions, and clinical data on complications of myocardial infarction. Findings demonstrate that the proposed evolutionary optimisation framework (‘ActiGen-MOGA’) was able to generate a novel scalable AF, which led to achieve the highest classification performance and the fastest convergence across six out of nine datasets. In the best classification task, the ActiGen-MOGA-based AF led to a classification performance of 80 % and 78 % higher than the polynomial and Rectified Linear Unit (ReLU) AFs respectively.
    • Bending performance of SFCBs reinforced UHPC beams prestressed with FRP bars

      Ge, W.; Zhang, F.; Sushant, S.; Ashour, Ashraf; Chen, K.; Fu, S.; Qiu, L.; Luo, L.; Cao, D. (Elsevier, 2025-07)
      This study investigates the bending performance of ultra-high-performance concrete (UHPC) beams reinforced with non-prestressed steel-FRP composite bars (SFCBs) and prestressed fiber-reinforced polymer (FRP) bars. The finite element software ABAQUS was used to simulate the strain behaviors of materials, applying a real strain model for concrete and equivalent plastic strain models for reinforcements. Six beams with different concrete types and reinforcements (prestressed or non-prestressed) were simulated and analyzed. These simulations yielded results that closely aligned with the results tested. Based on the validated FE models, a parametric analysis was conducted to examine the effects of mechanical properties of concrete, mechanical property of non-prestressed reinforcement, and the reinforcement ratio of prestressed FRP bars and non-prestressed SFCB on the bending performance of SFCBs reinforced UHPC beams prestressed with FRP bars. The results indicate that, as the concrete strength increases from C35 to UHPC140, both the bearing capacity and ultimate deflection of flexural beams exhibit a gradual increase. Notably, employing UHPC100 as the matrix results in specimens achieving the highest ductility, deformation, and energy absorption. When non-prestressed FRP bars are replaced by SFCBs, the ultimate load of the beams decreases by 8%, but energy absorption increases by 34%. With an increase in the steel ratio of SFCBs, the ductility, deformation, and energy absorption also gradually increase. Moreover, increasing the reinforcement ratio of both prestressed FRP and non-prestressed SFCBs results in an increase in bearing capacity, but a decrease in ultimate deflection, ductility, deformation, and energy absorption capacity. This research can provide valuable technical references for the analysis and design of UHPC beams reinforced with SFCBs and prestressed FRP bars.
    • Bending performance of reactive powder concrete frame beams reinforced with steel-FRP composite Bars

      Wang, Y.; Yao, Z.; Sushant, S.; Ashour, Ashraf; Ge, W.; Luo, L.; Qiu, L. (2025-07)
      To investigate the bending behavior of Steel-FRP Composite Bars (SFCBs) reinforced Reactive Powder Concrete (RPC) frame beams, both experimental and theoretical study were conducted on five concrete frame beams with different reinforcement ratio, types of concrete and reinforcement. The results indicate that the bending behavior of SFCBs-RPC frame beams progresses through three distinct stages: from loading to the cracking of tensile RPC, from cracking to the yielding of tensile SFCBs, and from yielding to failure. Compared with steel-reinforced RPC frames, the load of SFCBs-RPC frame beam continues to increase with the increase of deformation after the yielding of SFCBs, demonstrating good bearing capacity and ductility. Furthermore, the deformation and crack width of RPC frame beams are obviously lower than those of ordinary concrete frame beams, indicating the excellent deformation control and crack resistance ability of RPC beams. In addition, formulae for flexural stiffness at each stage were derived using the effective moment of inertia method. Taking the design code of reinforced concrete structure for reference and the tensile contribution of steel fibers and the mechanical performance of SFCBs into consideration, and the formulae for crack width of SFCBs-RPC flexural beam were developed. Formulae for the bearing capacity of SFCBs-RPC frame beams were also proposed on the base of simplified materials constitutive models and reasonable basic assumptions. The values predicted by these proposed formulae aligned well with the results tested. The research provides a theoretical support for the design and application of SFCBs-RPC frame beams.
    • Emerging trends in the Circular Economy: Multidimensional perspective in the building sector

      Finamore, Margherita; Oltean-Dumbrava, Crina (2025)
      The study is grounded in the Triple Bottom Line theory, which emphasizes three dimensions of accountability: environmental, social, and economic. However, the research on which the study is based argues that developing an effective framework for adopting the Circular Economy (CE) within the building sector requires a balanced consideration across four dimensions - environmental, social and economic, and technical - as the technical dimension plays a crucial role in the advancement of the CE concept. This complements previous research into the understanding of the CE concept in the building sector, further investigating these key dimensions that capture the evolution of CE research. Focusing specifically on the building sector, the research conducted a robust literature review examining the environmental, social, economic, and technical aspects associated with the CE concept . The aim of this was to identify existing barriers and gaps that prevent the successful adoption of a CE in the building sector. Insights derived from the literature review will then serve as the foundation for a new and comprehensive circular framework appropriate for the building sector. The research and study together thus underscore the importance of a four-dimensional, balanced framework for effectively implementing CE principles within the building sector.
    • Solid biomass chain from production to utilization in UK

      Samiee, Leila; Rahmanian, Nejat (2025)
      Bioenergy stands as the primary contributor within the realm of global renewables, offering energy security to a multitude of individuals while also fostering growth in rural areas. The emergence of fuel pellets derived from diverse feedstocks has brought forth both prospects and obstacles for current technologies. This article delivers an up-to-date examination of the production and application of fuel pellets sourced from biomass. The upcoming discourse will explore the various aspects, both positive and negative, of the production and utilization of fuel pellets obtained from biomass, with a specific focus on the circumstances in the United Kingdom (UK). Through acquiring a thorough understanding of the manufacturing procedures of fuel pellets, coupled with a detailed examination of their benefits and drawbacks, the feasibility of utilizing biomass can be greatly improved, consequently leading to a significant contribution to the progression of a sustainable bioenergy framework.
    • High-durability, low-carbon, and low-cost nano-engineered concrete for marine concrete infrastructures

      Sun, T.; Wang, X.; Ashour, Ashraf; Ding, S.; Li, L.; Han, B. (Elsevier, 2025-03)
      Traditional concrete fulfills the mechanical requirements for marine infrastructures but lacks durability. This study employed nano-engineering techniques to address the durability challenges in marine concrete infrastructures by enhancing the chloride ions penetration resistance of low- and medium-strength concrete to be comparable to that of high-strength concrete without increasing cement dosage. Meanwhile, nano-engineered concrete is also expected to reduce the cost and CO2 emissions of concrete structures over the life cycle. For this purpose, the effect and mechanisms of nanofillers on the durability and microstructures of concrete were investigated. Moreover, CO2 emission, cost, and sustainability of nano-engineered concrete were evaluated. The results indicated that a small content of nanofillers remarkably inhibited the penetration of chloride ions into concrete, without increasing cement content. The chloride ions diffusion coefficient of concrete with nanofillers is as low as 3.9010-12 m/s, representing a reduction of 62.8% compared to blank concrete. Moreover, nanofillers effectively refine the concrete microstructure by inducing hydration products into short rods, blocks, and lamellae. The thickness of the interfacial transition zones (ITZs) between cement mortar and gravel as well as cement paste and river sand decreases by 40.7%-55.9%/36.1%-47.4%, respectively, while the porosity of ITZs decreases by 8.7%-17.8%, after adding nanofillers. In addition, the cost and CO2 emission of nano-engineered concrete during production are reduced by 18.1%-27.8% and 14.4%-22.2%, respectively, compared to traditional concrete. These findings demonstrate that nano-engineered concrete can serve as a viable construction material with reasonable strength, high durability, low carbon footprint, and low cost for marine concrete infrastructures.
    • Technical Advancements Toward RIS-Assisted NTN-Based THz Communication for 6G and Beyond

      Amodu, O.A.; Nordin, R.; Abdullah, N.F.; Busari, Sherif Adeshina; Abu-Samah, A.; Otung, Ifiok; Ali, Muhammad; Behjati, M. (IEEE, 2024-12-04)
      The world is experiencing an explosion in demand for ultra-high data rates with far greater expectations in the next few years. These expectations, given the bandwidth-demanding applications such as augmented and virtual reality and other beyond-5G applications, motivate the exploration of higher-frequency communication in the terahertz (THz) bands. However, THz communication is faced with many technical challenges, primarily due to the high susceptibility to blockages that limit its applications. Here, reconfigurable intelligent surfaces (RIS) provide alternative paths to circumvent such blockage effects and ensure reliable, spectral, and energy-efficient communication, thus advancing the THz-RIS technology concept. However, the ambitious targets of ubiquitous and global connectivity can only be satisfied by many technologies extending to multiple domains, from terrestrial networks to non-terrestrial network (NTN) domains. The use of airborne and spaceborne networks is considered a potential solution for addressing these challenges due to their dynamism, coverage, and ability to leverage their altitude for achieving line-of-sight communication for enhanced signal quality and network performance. Therefore, unmanned aerial vehicles, high-altitude platform stations, and satellites are poised to use flying THz-based RISs to improve air-to-ground and space-to-ground communication reliability while exploiting novel RIS architectures, techniques and enablers to address the issues regarding the propagation conditions, hardware limitations, network complexity and system performance. The aim in this paper is to present the discussion and a survey on the technical advances on THz-RIS NTNs, in addition to outlining potential applications, architectural variants, influencing properties, as well as its prospects, associated challenges, open issues and future directions towards high-data rate THz-RIS NTN communication for 6G and beyond.
    • The Evolution of Biometric Authentication: A Deep Dive Into Multi-Modal Facial Recognition: A Review Case Study

      Abdul-Al, Mohamed; Kyeremeh, George Kumi; Qahwaji, Rami; Ali, N.T.; Abd-Alhameed, Raed (IEEE, 2024-12-09)
      This survey provides an insightful overview of recent advancements in facial recognition technology, mainly focusing on multi-modal face recognition and its applications in security biometrics and identity verification. Central to this study is the Sejong Face Database, among other prominent datasets, which facilitates the exploration of intricate aspects of facial recognition, including hidden and heterogeneous face recognition, cross-modality analysis, and thermal-visible face recognition. This paper delves into the challenges of accurately identifying faces under various conditions and disguises, emphasising its significance in security systems and sensitive sectors like banking. The survey highlights novel contributions such as using Generative Adversarial Networks (GANs) to generate synthetic disguised faces, Convolutional Neural Networks (CNNs) for feature extractions, and Fuzzy Extractors to integrate biometric verification with cryptographic security. The paper also discusses the impact of quantum computing on encryption techniques and the potential of post-quantum cryptographic methods to secure biometric systems. This survey is a critical resource for understanding current research and prospects in biometric authentication, balancing technological advancements with ethical and privacy concerns in an increasingly digital society.
    • Stochastic Expansion planning Model for a coordinated Natural gas and Electricity Networks Coupled with Gas-fired Generators, Power-to-Gas Facilities and Renewable Power

      Onen, Patrick S.; Zubo, R.H.A.; Ali, N.T.; Mokryani, Geev; Li, Jian-Ping; Abd-Alhameed, Raed (2024-07-29)
      This paper presents a stochastic expansion planning model for coordinated natural gas and electricity networks, incorporating gas-fired generators, Power-to-Gas facilities, and renewable power sources. The primary objective is to minimize the total cost over the planning horizon, addressing the significant interdependencies between these networks which, if planned independently, can lead to higher overall costs. The originality of this work lies in its comprehensive integration of both systems, leveraging their synergies to optimize infrastructure investment and operational efficiency. Methodologically, the model employs mixed integer linear programming (MILP) within the General Algebraic Modelling System (GAMS), using a Scenario Tree concept to account for the stochastic nature of renewable energy sources (RESs) and load variations. Data from an adapted twenty-node Belgium gas network and a sixteen-bus UK electricity distribution system were utilized. Results demonstrate substantial cost savings and improved system performance with the integrated approach, validating the model's effectiveness.
    • Preparation of flexible polymer sensor material by Spatial Confining Forced Network Assembly Micro Injection Molding

      Wang, X.; Zhou, S.; Whiteside, Benjamin R.; Wang, J.; Huang, Y.; Xu, H.; Sun, J.; Wu, D.; Coates, Philip; Gao, X. (2024)
      The development of high-performance flexible pressure-sensing materials necessitates the simultaneous achievement of exceptional flexibility, conductivity, and alignment of micro-nano structures with the mechanical response characteristics inherent to these materials. In this study, we propose a novel method for preparing flexible microneedles as a pressure-sensitive sensor array. Firstly, we obtain conductive composite particles through extrusion granulation, which consists of a compact conductive network with micron-scale filler as the skeleton and nano-filler filling in the gaps within the network. Moreover, by utilizing the ‘volume exclusion’ effect of the microneedle array on the micron-scale filler during injection molding, nanofillers dominate in entering the microneedle. As a result, our molded product exhibits high flexibility and moderate conductivity in its pressure-sensitive area, thereby providing ultra-high-pressure resistance along with desired response characteristics and sensitivity for sensors. Additionally, due to synergistic effects between microscale fillers and nano-fillers in non-pressure sensitive bases, a compact conductive network is formed that imparts sufficient conductivity to sensor materials. The method yields sensors with excellent repeatability, high dimensional accuracy, and good consistency, effectively addressing core application challenges of flexible sensors. The microstructure array flexible sensor fabricated using high-precision injection molding technology offers high efficiency, low cost, and scalability for mass production. Furthermore, the sensitivity of sensors produced by this method is significantly higher—26.6% greater than those made using traditional methods—with a sensitivity as high as 4.71kPa -1 .
    • Shear behavior of FRP-UHPC composite beams enhanced by FRP shear key: Experimental study and theoretical analysis

      Zhang, Z.; Ashour, Ashraf; Ge, W. (2024-11-11)
      To investigate the shear behavior of FRP (fiber reinforced polymers)-UHPC (ultra-high performance concrete) composite beams, four-point bending tests were conducted on seven FRP-UHPC specimens and two FRP-NSC (normal strength concrete) specimens, having different width and depth of concrete flange as well as FRP shear key (FSK) spacing. The slip between FRP profiles and concrete flange was controlled by employing FSK and epoxy resin bonded hybrid connection. The failure pattern, load-deflection/strain curves, and sliding response of composite beams were analyzed to study the influence of concrete type, FSK spacing, width and thickness of concrete slab. The results indicate that FRP-UHPC composite beams exhibited shear failure, while FRP-NSC composite beams experienced bending-shear failure. The composite beams demonstrated shear-lag effect, which became more pronounced with the increasing of the concrete slab width. The use of UHPC, reducing FSK spacing, and increasing the size of cross-section of concrete flange can effectively enhance the shear performance and reduce interface sliding. Formulae were developed to predict the shear capacity and deflection, considering shear deformation. The results predicted by the formulae developed match well with the experimental results.
    • Shear performance of poplar LVL beams with a hole in bending-shear spans

      Wang, A.; Zhang, Z.; Ashour, Ashraf; Liu, Y.; Wang, C. (2024-11-13)
      To investigate the shear performance of poplar laminated veneer lumber (LVL) beams with holes in bending-shear spans, six specimens were designed and tested by four-point bending tests. Among these, five specimens were provided with a single hole of varying diameter-to-height ratio in the bending-shear span and two of these beams were also reinforced with circumferential carbon fiber reinforced polymer (CFRP) wrap layers. Furthermore, a 3D finite element models for poplar LVL beams with a hole were established, based on the extended finite element method (XFEM) using ABAQUS software. The validated model was utilized to conduct parametric studies on the diameter-to-height ratio, the hole shape, and the vertical eccentricity ratio. A simplified theoretical analysis for predicting the cracking and ultimate loads for LVL beam with a hole was also proposed. The results indicated that beams without a hole failed due to bending, characterized by mid-span tension cracks, whereas beams with a hole exhibited shear failure along the beam's grain direction due to stress concentration around the holes. The maximum normal tensile strain perpendicular to grain around the hole had an angle of 45° or 225° relative to the beam's longitudinal axis, consistent with the crack initiation angle. As the diameter-to-height ratio increased, the cracking and ultimate loads of beams with a hole decreased, indicating more brittle failure characteristics. The circular hole beam showed significant improvements in cracking and ultimate loads compared with the square hole beam with side length equal to the diameter of the circular hole. When the hole center's vertical eccentricity was in the compression zone, an increase in vertical eccentricity led to enhancements in both the cracking load and ultimate loads. Wrapping the beam with CFRP sheet around the hole effectively mitigated crack propagation, enhancing the load-bearing capacity of beams. The simplified formulas provided accurate prediction for the ultimate load, but highly overestimated the cracking and ultimate loads for poplar LVL beams with a hole. The research findings can be provided as a technical support for the design and application of LVL beams with holes.
    • A review on the potential application of ultra-high performance concrete in offshore wind towers: Insights into material properties, mechanisms, and models

      Zhou, X.; Yu, F.; Ashour, Ashraf; Yang, W.; Luo, Y.; Han, B. (Elsevier, 2025-02)
      Ultra-high performance concrete (UHPC), characterized by its high strength and toughness as well as durability, provides a promising solution for the construction of offshore wind towers (OWTs). This paper comprehensively reviews the durability and the dynamic mechanical properties of UHPC for OWTs under the impacts of the marine environment. Furthermore, the modifying effects of additives, including supplementary cementitious materials (SCMs) and reinforcing fibers, as well as nanofillers on UHPC are explored. Overall, UHPC possesses a dense microstructure that impedes the intrusion of harmful substances, and owing to the incorporation of additives, UHPC exhibits outstanding dynamic mechanical properties, making it an ideal material for applications in OWTs subjected to vibration fatigue and dynamic impact loads. Incorporating SCMs into UHPC can improve the durability and environmental benefits while maintaining similar dynamic mechanical properties concurrently. Nanofillers can serve as a beneficial supplement to steel fibers providing improved durability and dynamic mechanical properties by endowing UHPC dense microstructure and high system energy. Various models of marine environmental and loading actions on UHPC, examining ion transport, matrix degradation, and constitutive models, are concluded to gain insight into the underlying destructive mechanisms. These underlying mechanisms and the theoretical models further deepen the understanding of the service performance of UHPC in marine environments, thus providing the design guidance for the potential applications of UHPC in OWTs.
    • Natural language processing-driven framework for the early detection of language and cognitive decline

      Panesar, Kulvinder; Perez Cabello de Alba, M.B. (Elseveir, 2023-12)
      Natural Language Processing (NLP) technology has the potential to provide a non-invasive, cost-effective method using a timely intervention for detecting early-stage language and cognitive decline in individuals concerned about their memory. The proposed pre-screening language and cognition assessment model (PST-LCAM) is based on the functional linguistic model Role and Reference Grammar (RRG) to analyse and represent the structure and meaning of utterances, via a set of language production and cognition parameters. The model is trained on a DementiaBank dataset with markers of cognitive decline aligned to the global deterioration scale (GDS). A hybrid approach of qualitative linguistic analysis and assessment is applied, which includes the mapping of participants´ tasks of speech utterances and words to RRG phenomena. It uses a metric-based scoring with resulting quantitative scores and qualitative indicators as pre-screening results. This model is to be deployed in a user-centred conversational assessment platform.
    • Experiment and numerical modelling of a demountable steel connection system for reuse

      Dai, Xianghe; Yang, Jie; Lam, Dennis; Sheehan, Therese; Zhou, Kan (2022-11)
      Currently, steel reuse is only a marginal practice. To facilitate deconstruction and efficient reuse of steel components, an innovative connection system was proposed. This system adopts a ‘Block Shear Connector (BSC)’ that allows beam length to be standardised and suitable for a wide range of different sizes of the supporting members within the same planning grid. This paper presents the experimental and numerical studies of a beam-to-beam connection using BSCs. The BSC used was made from a standard universal HE / UC section and was bolted to the beams by using partial depth end plates. The experimental results provided the shear resistance, momentrotation, failure behaviour, demountability and reusability of the steel components. Further numerical simulation conducted investigated the effect of some key parameters (steel strength, thickness of BSC web, thickness of BSC flange, initial bolt stress) on the behaviour of the connections. The results obtained highlighted the demountability of this innovative bolted connection system and the reusability of structural components.
    • An NLP-based framework for early identification of design reliability issues from heterogeneous automotive lifecycle data

      Uglanov, Alexey; Campean, Felician; Abdullatiff, Amr R.A.; Neagu, Ciprian Daniel; Doikin, Alexandr; Delaux, David; Bonnaud, P. (2024-10-15)
      Natural Language Processing is increasingly used in different areas of design and product development with varied objectives, from enhancing productivity to embedding resilience into systems. In this paper, we introduce a framework that draws on NLP algorithms and expert knowledge for the automotive engineering domain, to extract actionable insight for system reliability improvement from data available from the operational phase of the system. Specifically, we are looking at the systematic exploration and exploitation of automotive heterogeneous data sources, including both closed-source (such as warranty records) and open-source (e.g., social networks, chatrooms, recall systems) data, to extract and classify information about faults, with predictive capability for early detection of issues. We present a preliminary NLP-based framework for enhancing system knowledge representation to increase the effectiveness and robustness of information extraction from data, and discuss the temporal alignment of data sources and insight to improve prediction ability. We demonstrate the effectiveness of the proposed framework using real-world automotive data in a recall study for a vehicle lighting system and a particular manufacturer: four recall campaigns were identified leading to corrective actions by the warranty experts.
    • Cavitation in die drawn poly(4-methyl-1-pentene) during second-stage tensile deformation

      Han, C.; Lyu, D.; Lu, Y.; Caton-Rose, Philip D.; Coates, Philip D.; Men, Y. (Elsevier, 2024-02-19)
      Pre-oriented poly (4-methyl-1-pentene) samples were prepared by the die drawing process. The stress whitening phenomenon induced by cavities in the different die drawn P4M1P samples during the second-stage tensile deformation was investigated at temperatures below and above Tg. At 30 °C and 50 °C, the cavitation process near yield point is influenced by the fraction of unoriented crystalline phase in pre-oriented samples. Cavities originate from the fracture of the crystalline skeleton at small strains were observed in the sample with a high fraction of unoriented crystalline phase. At high deformation temperature, the small strain cavities were suppressed and the cavitation processes in all die drawn samples are due to the failure of the highly oriented fibrillar network caused by the breaking of the load-bearing interfibrillar/microfibrillar tie molecule chains.
    • Deformation Temperature Dependency of Microstructure Evolution in Die-Drawn iPP/UHMWPE Blends

      Qin, X.; Lu, Y.; Lyu, D.; Caton-Rose, Philip D.; Coates, Philip D.; Men, Y. (ACS, 2024-10-08)
      Ultrahigh molecular weight polyethylene (UHMWPE) is one of the most promising polyolefins, but its processability and consequently applications are limited by its high melt viscosity. An effective method to improve the processability is to introduce another polymer component. Yet it is challenging to deform the sample if the components are not compatible with each other. In this work, we blended the UHMWPE with isotactic polypropylene (iPP) and successfully processed the iPP/UHMWPE samples via die-drawing at temperatures below, near, and above the melting temperature of UHMWPE. It was found that the melting behavior of the die-drawn samples was determined by the deformation temperature. The molecular chain orientation slightly decreased, while the long periods first increased and then decreased with increasing deformation temperature. Three melting peaks observed in the samples deformed at 130 and 140 °C originated from the melting of cooling-induced UHMWPE crystallites, deformation-induced fibrillar UHMWPE crystallites, and deformation-induced fibrillar iPP crystallites, respectively. The melting peak of deformation-induced fibrillar UHMWPE crystallites could not be observed in the sample deformed at 150 °C because it is unlikely for UHMWPE chains to crystallize at such a high temperature. This sample also has the lowest melting point since the UHMWPE lamellae formed during deformation could serve as nucleation sites in the other two samples.