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Ni‐promoted electrocatalytic biomass reforming has shown promising prospect in enabling high value‐added product synthesis. Here, we developed a novel hybrid catalyst with Ni nanosheet forests anchored on carbon paper. The hybrid catalyst exhibits high efficiency in electrooxidation of HMF to FDCA coupling with H2 production in high purity. The Ni nanosheets have small crystal grain sizes with abundant edges, which is able to deliver an efficient HMF oxidation to FDCA (selectivity >99 %) at low potential of 1.36 VRHE with high stability. The post‐reaction structure analysis reveals the Ni nanosheets would transfer electrons to carbon and readily turn into NiOx and Ni(OH)x during the reaction. DFT results suggest high valence Ni species would facilitate the chemical adsorption (activation) of HMF revealing the reaction pathway. This work emphasizes the importance of the precise control of Ni activity via atomic structure engineering. [ABSTRACT FROM AUTHOR]

Engineering structures consume a significant fraction of resources and contribute to greenhouse gas emissions worldwide. A conducted literature review shows that most existing approaches to improve the environmental performance of structures concern the adoption of decisions during the conceptual design stage (e.g. on the choice of material), often in connection with life cycle assessment. However, approaches for addressing environmental objectives in practice are often hampered by economic interests pursuing short-term profit. Moreover, such approaches are rather descriptive and lack criteria for assessing the acceptability of specific solutions. Sustainable development of our built environment requires hence a shift of paradigm on how engineering structures are designed. In this paper it is claimed that this should be approached at the strategical level of structural design codes, which contain the rules that support everyday engineering decisions in regard to structural safety and functionality. The paper discusses the reasons why these rules as conceived do not foster an optimal use of materials and explores possibilities for savings of resources and greenhouse gas emissions through modifications of these rules. The potential of risk-informed decision approaches in this context is highlighted and illustrated by a case study – the design of steel beams in building structures. [ABSTRACT FROM AUTHOR]

Purpose: This study seeks to understand the connection of methodology by finding relevant papers and their full review using the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA). Design/methodology/approach: Concrete-filled steel tubular (CFST) columns have gained popularity in construction in recent decades as they offer the benefit of constituent materials and cost-effectiveness. Artificial Neural Networks (ANNs), Support Vector Machines (SVMs), Gene Expression Programming (GEP) and Decision Trees (DTs) are some of the approaches that have been widely used in recent decades in structural engineering to construct predictive models, resulting in effective and accurate decision making. Despite the fact that there are numerous research studies on the various parameters that influence the axial compression capacity (ACC) of CFST columns, there is no systematic review of these Machine Learning methods. Findings: The implications of a variety of structural characteristics on machine learning performance parameters are addressed and reviewed. The comparison analysis of current design codes and machine learning tools to predict the performance of CFST columns is summarized. The discussion results indicate that machine learning tools better understand complex datasets and intricate testing designs. Originality/value: This study examines machine learning techniques for forecasting the axial bearing capacity of concrete-filled steel tubular (CFST) columns. This paper also highlights the drawbacks of utilizing existing techniques to build CFST columns, and the benefits of Machine Learning approaches over them. This article attempts to introduce beginners and experienced professionals to various research trajectories. [ABSTRACT FROM AUTHOR]

Mixed multiple seismic systems (MMSSs) are ideally suited for sustainable seismic design (SSD). MMSSs are combinations of two or more different earthquake-resisting structures (ERSs) that provide lateral support for gravity frameworks. Same-system combinations have been demonstrated to not be suitable for SSD. Regardless of the carbon footprint reduction, unless a structure has been designed for seismic sustainability it would be disposable with greater harm to the environment. Here, design means planning for both seismic resistance as well as post-earthquake realignment and repair (PERR). Earthquakes are random, natural, and dynamic events, whereas PERR is a deliberate, manual, and static process. In SSD the practicality of PERR is as important as the relevance of the theoretical assumptions. In SSD the non-lateral-resisting items are designed not to partake in seismic resistance, nor hinder the realignment process. Additionally, efforts are made to mitigate the P -delta effects that undermine the global strength of the system and oppose the recentering effort. The purpose of this paper is to identify and remedy design flaws and physical issues that prevent MMSSs from achieving seismic sustainability as cost-effectively as possible. Two newly developed technologies, the ladder moment frame (LMF), and the fail-safe (FS) system, as well as a capacity distribution rule together with six simple axioms are introduced. Brief descriptions of LMF and FS are presented in the text. Any structure designed to survive earthquakes is expected to either remain elastic and stable or be capable of post-earthquake realignment and repairs. Sustainable seismic design is a new field of research that promises improved environmental conditions and innovative developments in structural engineering. Regardless of the carbon footprint reduction, unless a structure has been designed for the purpose, it would be disposable with greater harm to the environment. Here, design implies planning for seismic resistance as well as post-earthquake realignment and repairs. The difference between conventional and sustainable seismic design is in the modes of behavior during and after the event. In conventional seismic design, the object is to satisfy code-specified requirements; in sustainable seismic design, the post-earthquake attributes of the system are as important as those during the event. The paper shows that seismic sustainability can be achieved without resorting to untenable costs and technologies. In light of current findings, it is suggested to include post-earthquake realignment and repairs in seismic design guidelines for new construction. [ABSTRACT FROM AUTHOR]

This paper shows current trends in testing and numerical analysis of dynamic loading in relation to a real frame foundation for a turbogenerator set. The analysis of the machine's foundations, which are subjected to static and dynamic loads, is a complex problem combining the issues of geotechnics, structural engineering, and vibration theory. The authors present a case study of the assessment of the foundation's technical condition. The main objective of this study is to perform and compare experimental and numerical dynamic analysis which includes the measurement of the acceleration, speed, and amplitude of the natural vibrations of the foundation during the operational speed of the turbogenerator. In addition, auxiliary material tests were carried out to fully diagnose the foundation and obtain the material properties required for the numerical analysis. They included both destructive and non-destructive of concrete strength, the evaluation of the degree of its carbonation, and the scanning of the reinforcement distribution. The research presented in the paper is intended to facilitate the preparation of appropriate data for the design of the foundation renovation and strengthening. [ABSTRACT FROM AUTHOR]

To promote precision installation accuracy of engineering structural components and improve construction quality, point cloud data obtained by 3D laser scanning are widely used in construction quality monitoring. Reasonable parameters are very important to control errors and improve efficiency during the process of 3D laser scanning. Therefore, this paper proposes a random forest-nondominated sorting genetic algorithm (RF-NSGA-II) multiobjective optimization model with an elite strategy. To study the relationship between 3D laser scanning parameters and measurement errors or efficiency, the best scanning parameters are identified. In this paper, high-precision prediction of the relative error and scanning time by 3D laser scanning parameters is achieved by using an RF, and the nonlinear mapping relationship function is obtained, which is used as the objective optimization function. The RF-NSGA-II multiobjective optimization algorithm is developed to optimize the relative error and scanning time, and the scanning time is the shortest under the condition of reasonable relative error. Through this study, we can mainly draw the following conclusions: (1) based on the RF, we can obtain a prediction model of relative error and scanning time with high accuracy, in which the R2 (determination coefficient) value and root mean square error (RMSE) of the relative error prediction model are 0.967 and 0.0277, respectively, and the R2 value and RMSE of the scanning time prediction model are 0.978 and 0.0243, respectively; (2) optimized design parameters for 3D laser scanning of structural components are obtained, including a horizontal incident angle of 90°, an inclination angle of 90°, point cloud density of 3.2 mm, measurement distance of 3 m, resolution of 0.456, and visibility of 8.67 km; and (3) the RF-NSGA-II model developed can effectively reduce the relative error of the 3D laser (by 2.16 mm) and shorten the scanning time (by 148.926 s) compared with the average value. The structural components also meet the requirements in the deviation test. Therefore, the application of the RF-NSGA-II model in the assembly and fabrication of structural components can realize the intellectualization of the production process and improve the precision of the prefabrication of structural components, which has high engineering application value. [ABSTRACT FROM AUTHOR]

This work presents a global surrogate modelling of mechanical systems with elasto-plastic material behaviour based on support vector regression (SVR). In general, the main challenge in surrogate modelling is to construct an approximation model with the ability to capture the non-smooth behaviour of the system under interest. This paper investigates the ability of the SVR to deal with discontinuous and high non-smooth outputs. Two different kernel functions, namely the Gaussian and Matèrn 5/2 kernel functions, are examined and compared through one-dimensional, purely phenomenological elasto-plastic case. Thereafter, an essential part of this paper is addressed towards the application of the SVR for the two-dimensional elasto-plastic case preceded by a finite element method. In this study, the SVR computational cost is reduced by using anisotropic training grid where the number of points are only increased in the direction of the most important input parameters. Finally, the SVR accuracy is improved by smoothing the response surface based on the linear regression. The SVR is constructed using an in-house MATLAB code, while Abaqus is used as a finite element solver. [ABSTRACT FROM AUTHOR]

Structural health monitoring plays a crucial role in ensuring the integrity and safety of engineering structures such as steel beams. This research paper presents a comprehensive methodology for detecting transverse cracks in beams with a constant section and any boundary conditions. The proposed approach utilizes the normalized squared modal curvature of the beam, the damage severity, and the natural frequency of the undamaged beam. By analyzing the natural frequencies of both the undamaged and damaged states, Relative Frequency Shift (RFS) values are obtained. Subsequently, the Damage Location Coefficients (DLC) are calculated by normalizing the RFS values. These DLC values are then employed to establish a comprehensive database of known damage signatures, enabling the training of an artificial neural network (ANN) in MATLAB. The trained ANN can predict the locations of damages for new scenarios by utilizing DLC values obtained from measurements. To validate the effectiveness of the ANN, extensive simulations using Finite Element Method (FEM) and experimental measurements are conducted on a steel cantilever beam. The results demonstrate the ANN's capability to accurately predict the locations of transverse cracks, showcasing its potential as a reliable tool for structural health monitoring of steel beams. [ABSTRACT FROM AUTHOR]

High-strength steel (HSS) has been increasingly applied in structural engineering, while the work on residual stress of HSS sections is still insufficient. Limited research is available for welded H-sections above 690 MPa while with a plate thickness of more than 10 mm. This paper deals with the residual stress distributions of welded H-sections with flame-cut edges, which are fabricated from HSS plates with yield strength of 690 MPa and 960 MPa and thickness of 10 mm–20 mm, using both experimental and numerical method. The experiments showed that the welded tensile residual stresses in the weld region are not significantly affected by sectional dimensions and steel grade. Verified by comparing with the experimental results, three-dimensional (3D) finite element (FE) models using sequentially coupled thermal-stress analysis was adopted for parametric study of compressive residual stress of welded H-sections made of 690 MPa HSS. The results showed that the compressive tensile stress is negatively correlated with plate thickness as well as width-thickness ratio. Through regression analysis, formulae were proposed for estimation of compressive residual stress in the flange and web, respectively. Finally, residual stress distribution model was developed, which was proved effective by comparing with the experimental and FE results. [ABSTRACT FROM AUTHOR]

Operational modal identification of time-varying systems plays a crucial role in assessing the health condition and controlling the dynamic properties of engineering structures. However, only the response is measurable, making it challenging. Based on the variational mode decomposition (VMD) theory, this paper presents a short-time multivariate or multi-channel VMD (STMVMD) method for instantaneous frequency (IF) identification of time-varying structures in the case of output-only measurements. The idea of short-time windows overcomes the shortcoming of many VMD-based methods that employ the narrowband assumption of intrinsic mode functions (IMFs) and cannot decompose non-stationary signals involving closely-spaced wideband IMFs. After obtaining the multivariate IMFs by STMVMD, an average scheme is employed to estimate IFs, reducing the noise sensitivity of Hilbert Transform. Moreover, by tracking the center frequencies of STMVMD at different moments, another more noise-robust IF estimation method is also presented. A series of numerical and experimental examples illustrate the advantages of the proposal. [ABSTRACT FROM AUTHOR]

In this paper, laser-induced breakdown spectroscopy (LIBS) combined with a probabilistic neural network (PNN) was applied to classify engineering structural metal samples (valve stem, welding material, and base metal). Additionally, utilizing data from the plasma emission spectrum generated by laser ablation of samples with different aging times, an aging time prediction model based on a firefly optimized probabilistic neural network (FA-PNN) was established, which can effectively evaluate the service performance of structural materials. The problem of insufficient features obtained by principal component analysis (PCA) for predicting the aging time of materials is addressed by the proposal of a time-frequency feature extraction method based on short-time Fourier transform (STFT). The classification accuracy (ACC) of time-frequency features and principal component features was compared under PNN. The results indicate that, in comparison to the PCA feature extraction approach, the time-frequency feature extraction method based on STFT demonstrates higher accuracy in predicting the time of aging materials. Then, the relationship between classification accuracy (ACC) and settings of PNN was discussed. The ACC of the PNN model for both the material classification test set and the aging time test set achieved 100% with Firefly (FA) optimization algorithms. This result was also compared with the ACC of ANN, KNN, PLS-DA, and SIMCA for the aging time test set (95%, 87.5%, 85%, and 62.5%, respectively). The experimental results demonstrated that the classification model using LIBS combined with FA-PNN could realize better classification accuracy. [ABSTRACT FROM AUTHOR]

Jointed rock masses are a common phenomenon in rock engineering and are vulnerable to cyclic loads caused by earthquakes, blasts, and traffic loads. Therefore, it is crucial to comprehend the fatigue characteristics of jointed rock masses under dynamic cyclic disturbance for long‐term stability assessments of rock engineering structures. This paper aims to investigate the effects of distinct joint inclinations under pre‐cyclic loading on the strength and failure characteristics of rock‐like specimens using experiments and numerical simulations. The results indicate that cyclic loading decreases the strength of the specimen, and the strength characteristics of the specimen are more apparent as the joint inclination angle becomes smaller. Furthermore, insights into different upper limit stress fatigue behaviors were gained by analyzing strength characteristics, crack propagation characteristics, and failure modes. Numerical results show that the damage degree of cyclic loading at high‐stress levels is linked to the joint inclination angle and carrying capacity of specimens, and high cycle stress levels have an impact on the failure mode of the specimen. Highlights: The damage degree of jointed specimens at different upper limit stress cyclic levels was investigated.The sensitivity of jointed specimens to cyclic stress‐level damage was revealed.The macro and meso fatigue behaviors of jointed specimens were discussed. [ABSTRACT FROM AUTHOR]

The vision for fib MC2020 is to go beyond the point reached by fib MC2010, recent ISO codes, such as ISO 16311, and the current Eurocode activities to extend the application of Eurocodes to existing structures. The contents of fib MC2020 suit these forward‐looking objectives, dealing both with the design of new structures and all the activities associated with the life‐cycle management of existing concrete structures including matters, such as in‐service assessment and interventions upon them, including situations where new structural members are incorporated as parts of existing structures. With the fib MC2020 adaptations taking sustainability as a fundamental requirement, defining implications for subsidiary performance requirements critical to structural design and assessment procedures, it is logical that Model Code 2020 explicitly introduces and consequently seeks to make use of performance‐based concepts. A focus on performance provides a potential way to better align the interests of owners, users, technical consultants (such as structural engineers, material engineers, etc.), contractors, as well as material suppliers and manufacturers. It is envisaged that implementing the concept of the performance‐based approach in design and assessment will encourage rational design and technological progress which will facilitate the creation of superior structures for future generations, by removing constraints to the use of novel types of concrete and reinforcing materials and offering possibilities for optimization of solutions that better fit the needs of stakeholders. This paper addresses the principles of the performance‐based approach to design and assessment and discusses the manner in which it has been introduced in fib MC2020. The benefits and burdens associated with the performance‐based approach and the traditional prescriptive approach to engineering specification are discussed, both from a technical and process/commercial/contractual point of view, to describe the overall benefits of the performance‐based approach. Finally, the future outlook for a coherent integration of the performance‐based approach in design and assessment is addressed, paving the way for further work on standardization for sustainable concrete structures. [ABSTRACT FROM AUTHOR]

Mobilisation of alternate load path (ALP) mechanisms in three-dimensional (3D) beam–slab systems is a key factor in designing structures against progressive collapse. Existing analytical methods on 3D beam–slab systems focusing on limited load-resisting mechanisms often lead to uneconomical and unrealistic design, while finite element models with 3D solid elements are too complicated and time-consuming for 3D beam–slab systems. To address these shortcomings, this paper aims to provide structural engineers with two simple but effective and reliable approaches to predict the structural behaviour of 3D beam–slab systems. They include (i) an analytical method and (ii) a simplified finite element model based on strip method and grillage analysis. Both approaches are validated against published test results for 3D beam–slab systems. Compared to existing approaches on 3D beam–slab systems, these two proposed methods incorporate all the load-resisting mechanisms in both the beams and slabs, giving more accurate and realistic predictions of load–displacement curves for the sub-structures considered. In addition, parametric studies on the analytical approach are presented to shed light on the role of boundary conditions and the contribution of slabs to the load resistance capacity of 3D beam–slab structures against progressive collapse. [ABSTRACT FROM AUTHOR]

Steel is the most widely used structural material in engineering applications. It has high strength and elasticity. But the major problem with steel is that it corrodes when comes in contact with the atmosphere. To avoid corrosion many techniques have been developed over the years. Coating the surface of steel with a non-corrosive element is the most common method. However, the currently used methods are expensive and need very controlled environmental conditions. In this paper, the dip coating method for coating zinc on mild steel is studied. The hardness of the surface after coating in measured and immersion tests was conducted. It was observed that the zinc coating done through the dip coating process could reduce the corrosion. This proves that the dip coating is an effective method to apply coating on mild steel. This method also has the advantage of lesser expenses. [ABSTRACT FROM AUTHOR]

This paper presents the formulation of a novel fire spread model to allow the study of traveling fires in large open spaces. The fuel load for an office building, for example, is made up of clusters of workstations that are arranged in a realistic pattern on the floor plan. The fire begins with the assumed ignition of a single workstation. The fire dynamics are modeled using computational fluid dynamics (CFD) software, which allows the user to specify exact compartment parameters, such as the compartment size, wall lining, ventilation conditions, and fuel load distribution. To reduce computational expense, each object (e.g., workstation) is represented by a burner that has a heat release rate equivalent to a complete workstation, as determined by experimental tests. The fire is allowed to spread realistically from object to object through the use of an improved flux-time product ignition model. The improved flux-time product ignition model is derived to predict ignition under time-varying heat flux exposure and only requires well-documented material properties for implementation. The study validates the equivalent burner assumption and the flux-time product fire spread model for large compartments using experimental data from NIST (Hamins A (2005) Experiments and modeling of multiple workstations burning in a compartment. Nist Ncstar.). The proposed fire spread model for large compartments aims to provide more realistic fire behaviors for fire resistant design of structures while balancing accuracy with computational efficiency. [ABSTRACT FROM AUTHOR]

Geosynthetics have been commonly used for the construction of civil engineering structures such as retaining wall, road and railways, coastal protection, soft ground improvement work, and landfill systems since the 1960s. In the past 40 years, the development of polymer materials has helped to prolong the life of geosynthetics. In terms of the practical use of geosynthetics, engineers must understand their appropriate application. The first part of this paper provides a basic description of geosynthetics, including their types, components, and functions. The second part deals with the geosynthetics used as filters. This part briefly presents the mechanism of filtration, the factors affecting the durability of geotextile filters, design concepts, laboratory tests, and case studies. The third part of the study covers the use of geosynthetics for stabilisation. Its mechanism was explained separately for geogrids and for geocells. Several examples of applications with geosynthetics intended for the stabilisation function are described in the last part of this paper. [ABSTRACT FROM AUTHOR]

Fillet welded joints are commonly used in steel structures for various engineering applications such as buildings, bridges, railways, ships, and marine structures. Fillet welded joints are generally subjected to static and fatigue loading, resulting in failures of such welded joints. A number of experimental and numerical investigations on the strength and failure behaviour of fillet welded joints have been published. This paper presents a comprehensive review of research results on the static strength, fatigue life, and thermal performance of fillet welded joints. The review covers the various influential factors, such as loading direction, weld geometry, grades of steel, filler materials, welding process, weld penetration, strength mismatch of weld metal, and post-welded treatment. In total, 100 papers were critically reviewed, which were published from 1970 till date. The key findings and research developments on fillet welded joints are summarised. It was found that the transverse fillet welded joints have a higher static strength than the longitudinal fillet welded joints. Filler materials, post-welded treatment, and penetration of weld metal can offer significant strength enhancements in terms of their static and fatigue strength. Lastly, research gaps have been found in the existing body of knowledge, which will help guide future research. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to reveal the corrosion mechanism and corrosion development regulation of marine engineering structural steel in the marine environment and provide constructive suggestions for marine immersed tunnel engineering. Design/methodology/approach: In this study, marine engineering structural steel's behavior and corrosion prediction were carried out under the conditions of no cathodic protection and under-protection by artificially adding dissolved oxygen in a simulated seawater solution as a depolarizing agent. Findings: Marine resources are rich in China. With the development of the economy and the improvement of engineering technology, marine engineering structural steel is used more and more widely. Engineering structural steel has a great risk of corrosion failure for long-term service in seawater, as seawater is a kind of corrosive medium containing various salts. At present, there are few projects and research studies available on the corrosion in the seawater environment of Q390C engineering structural steel, which is used in the Shenzhen–Zhongshan Link immersed tunnel steel shell at home and abroad. It cannot guide the corrosion of immersed tunnel steel shells in the ocean. Originality/value: In this paper, the corrosion mechanism and corrosion development regulation of marine engineering structural steel in the marine environment are studied by accelerated corrosion test in the laboratory, which is of great significance to ensure the long-life durability of the immersed tunnel in marine engineering. [ABSTRACT FROM AUTHOR]

• The dynamic model of a truss antenna with two arms is established using proposed folded beam-ring structure. • The analytical global mode shapes of the folded beam-ring structure are derived and verified. • The influences of the geometrical and physical parameters on frequencies of the system are demonstrated. • The method presented in this paper can be applied to dynamic analyses of other similar complex engineering structures. The large-aperture hoop truss antenna is considered as an ideal deployable antenna, whose dynamic performance largely limits the practical application. Extracting a reasonable and solvable model is the essential prerequisite and foundation for analyzing the dynamic characteristics of an antenna. In this paper, a folded beam-ring structure composed of two beams and one ring is proposed to model a hoop truss antenna. The governing equations of motion and boundary conditions for the folded beam-ring structure are derived by using the Hamilton principle. After applying the method of separation of variables, the frequencies and global mode shapes are theoretically calculated by solving the linear parts of governing equations and boundary conditions. The reliability of dynamic model proposed for the folded beam-ring structure is proven by comparison of frequencies and mode shapes. The influences of geometrical and physical parameters on natural frequencies of folded beam-ring structures are analyzed. The parametric rule of frequencies is important for analyzing the resonant relations of the structure. The analytical global mode shapes are beneficial for constructing precise nonlinear dynamic model for the antenna system. And the modeling method presented here can be used as a reference to dynamic analyses of other complex structures. [ABSTRACT FROM AUTHOR]

This paper presents a review of composite structures in which aluminium alloys are used. Current trends in the research of composite structures with aluminium girders and their possible applications in structural engineering were shown. In the presented solutions, advantageous properties of aluminium alloys were exploited, such as high strength-to-weight ratio, corrosion resistance and recyclability. The authors demonstrated the structural behaviour of aluminium-concrete and aluminiumtimber composite beams based on their own tests as well as investigations presented in the literature. Furthermore, aluminium-concrete composite columns, a composite mullion made of an aluminium alloy and timber, and a military bridge consisting of aluminium truss components, a stay-in-place-form, reinforcement and concrete were presented. In addition to the description of the structural elements, the main conclusions from their experimental, theoretical and numerical analyses were also demonstrated in this paper. The connection of aluminium girders with concrete or timber slabs provided for the increase of the load-bearing capacity and stiffness, and it eliminated the problem of local buckling in girder flanges and lateral-torsional buckling of girders in the analysed solutions. [ABSTRACT FROM AUTHOR]

This editorial highlights six papers published in the Proceedings of the Institution of Civil Engineers: Structures & Buildings. The topics covered include the bond properties of steel rebars in cracked concrete, flexural strengthening of reinforced concrete beams, repairing fire-damaged circular RC columns, seismic performance of a connection between concrete-filled steel columns and RC frames, optimal sensor placement for detecting rail damage, and the mechanical behavior of fasteners in laminated bamboo lumber. The papers present experimental and theoretical research, providing valuable insights into various aspects of civil engineering. [Extracted from the article]

Reinforced concrete (RC) is a widely used construction material due to its superior characteristics compared to steel and timber. It is commonly used in various civil engineering structures such as bridges, dams, and residential buildings. The mechanical behavior of reinforced concrete under different loading conditions remains a challenge, despite extensive research. This special issue explores theoretical, experimental, and numerical studies on the mechanical properties of reinforced concrete materials, including topics such as dynamic characteristics, antiknock performance, structural behavior, bond behavior, and modification of concrete aggregates. The research papers included in this special issue highlight the importance of global collaborations in advancing our understanding of reinforced concrete materials. [Extracted from the article]

Accuracy of deep learning model translation is a key index to evaluate the application performance of engineering English translation. In this paper, an automatic error detection system for English translation is proposed. In the particular task of grammar detection, researchers have gradually shifted their attention from statistical methods to neural network methods. Three deep learning algorithm models are established, and the multitask performance of the model is better than that of the conditional random field model and the LSTM-CRF model. The reason is that the multitask learning model of auxiliary tasks is included to some extent, which solves the problem of data sparsity and enables the model to be fully trained even under the condition of uneven label distribution. Thus, it performs better than other models in the task of syntax error detection. It realizes the word spelling error check based on the dictionary and uses the thought of editing distance to prompt the word error found, which can automatically check a large number of translations. On the basis of analyzing the sentence structure characteristics of engineering English translation, this paper realizes the detection of subject-verb agreement errors and analyzes the main word of the subject corresponding to the predicate verb by constructing the syntactic structure tree of the sentence, so as to realize the judgment of subject-verb agreement errors. [ABSTRACT FROM AUTHOR]

Purpose: For fast calculation of complex structure in engineering, correlations among input variables are often ignored in uncertainty propagation, even though the effect of ignoring these correlations on the output uncertainty is unclear. This paper aims to quantify the inputs uncertainty and estimate the correlations among them acorrding to the collected observed data instead of questionable assumptions. Moreover, the small size of the experimental data should also be considered, as it is such a common engineering problem. Design/methodology/approach: In this paper, a novel method of combining p-box with copula function for both uncertainty quantification and correlation estimation is explored. Copula function is utilized to estimate correlations among uncertain inputs based upon the observed data. The p-box method is employed to quantify the input uncertainty as well as the epistemic uncertainty associated with the limited amount of the observed data. Nested Monte Carlo sampling technique is adopted herein to ensure that the propagation is always feasible. In addition, a Kriging model is built up to reduce the computational cost of uncertainty propagation. Findings: To illustrate the application of this method, an engineering example of structural reliability assessment is performed. The results indicate that it may significantly affect output uncertainty whether to quantify the correlation among input variables. Furthermore, an additional advantage for risk management is obtained in this approach due to the separation of aleatory and epistemic uncertainties. Originality/value: The proposed method takes advantage of p-box and copula function to deal with the correlations and limited amount of the observed data, which are two important issues of uncertainty quantification in engineering. Thus, it is practical and has the ability to predict accurate response uncertainty or system state. [ABSTRACT FROM AUTHOR]

The application of steel trapezoidal corrugated web in steel-concrete composite girders has been widespread in building structures and has also appeared in bridges for a few decades, due to their advantageous mechanical properties. Embedding the trapezoidal web in the concrete slab leads to additional advantages such as omitting the welds of the top flange, a greater extent of the accordion effect and extra resistance in the load transfer between the two materials. Despite these advantages and their increasing use, there are not many experimental studies to analyse the behaviour of the embedded trapezoidal web and its involvement in shear connection resistance. In order to expand the experimental studies, laboratory tests are executed between 2017–18 at the Department of Structural Engineering of the Budapest University of Technology and Economics on large-scale test specimens, with a total number of 43 embedded specimens. The current paper introduces the executed test program, the analysed specimens, their specialties regarding the geometrical layout and the obtained results. The paper gives a quantitative comparison of the 43 specimens and evaluates the analysed shear connectors regarding their static performance. [ABSTRACT FROM AUTHOR]

Shear wall structures are widely used in high-rise buildings. However, the design process of shear wall structures suffers from inefficiencies. This paper introduces StructDiffusion, an end-to-end intelligent system for shear wall layout generation and analysis. The proposed approach tackles the layout design task by employing a novel diffusion model architecture to generate conditional images. Key components of the proposed method include pretrained diffusion models, ControlNet for conditional control, and LoRA for efficient adaptation. Notably, the method allows for architectural plan images and basic textual design conditions as inputs, enabling manipulation of the generated layouts by adjusting attributes such as building height and seismic intensity. To evaluate the quality of the model's design swiftly, this paper presents a comprehensive evaluation framework that incorporates perceptual and structural validity metrics. Through experimental analyses, this paper demonstrates the effectiveness of the proposed model in generating layouts, surpassing the capabilities of GAN-based methods. Furthermore, our study investigates model-specific parameter configuration, text-guided capabilities, code compliance, and computational efficiency. StructDiffusion significantly enhances the automation and intelligence of structural engineering workflows. The framework effectively addresses challenges associated with instability, data scarcity, and limitations in assessment. This pioneering application of diffusion models opens up promising avenues for advancing data-driven structural design. • Pioneering stable diffusion models to replicate human structural design expertise. • Generating tailored layouts by aligning text-based design conditions and image-based architectural layouts. • Integrating LoRA, a low-rank decomposition technique, to optimize training efficiency with limited data. • Proposing an evaluation metric combining image quality and structural design considerations for robust model assessment. [ABSTRACT FROM AUTHOR]

Welded tubular joints are integral components in various engineering structures, subject to cyclic loading conditions throughout their operational lifespan. This paper investigates the evolution of welding residual stresses within the CHS X-joint and CHS double K-joint under cyclic loading, shedding light on their intricate behavior and potential implications for structural integrity. The advanced XRD experimental technique enables the characterization and monitoring of residual stress variations over multiple loading cycles. Assisted by the non-destructive XRD measurements, this study validates the optimization-improved thermal-mechanical simulation method for predicting not only the as-welded residual stresses in the tubular joints but also the residual stress evolutions during the cyclic loading tests. The most pronounced relaxation of peak residual stresses in the tubular joints occurs within the first cycle and then maintains a relatively stable magnitude in subsequent cycles. The findings of this research contribute to the enhancement of structural reliability and serve as a foundation for mitigating the adverse effects of welding residual stresses in welded tubular joints under cyclic loading scenarios. • This paper reports the experimentally measured residual stress during cyclic loads. • The residual stresses in both X and DK CHS joints relax significantly within 1st cycle. • Numerical analyses predict closely the evolution of residual stresses under cyclic actions. [ABSTRACT FROM AUTHOR]

Structural damage is inherent in civil engineering structures, and bridges are no exception. It is vital to monitor and keep track of damage in bridge structures as a result of multiple mechanical, environmental and traffic-induced factors. Monitoring the formation and propagation of structural damage is also pertinent for enhancing the service life of bridges. Bridge health monitoring (BHM) has always been an active research area for engineers and stakeholders. While all monitoring techniques intend to provide accurate and decisive information on the remaining useful life, safety, integrity and serviceability of bridges, maintaining uninterrupted operation of a bridge relies strongly on understanding the development and propagation of damage. BHM methods have been extensively researched on bridges over the decades, and new methodologies have started to be used by domain experts, especially within the last decade. Emerging methods, as the products of technology advancements, have resulted in handy tools that have been quickly adopted by bridge engineers. State-of-the-art techniques such as lidar, photogrammetry, virtual reality, augmented reality, digital twins, computer vision, machine learning and deep learning are now integrated parts of the new-generation of BHM operations. This paper presents a brief overview of these latest BHM technologies. [ABSTRACT FROM AUTHOR]

This paper proposes a plasmonic grating-based Refractive index sensor. A defect region is set up in the plasmonic grating. A special transmission mode near λ = 1550 nm is excited in the stop band of the plasmonic grating. When a nano-metallic slit is introduced in the defect region, a special resonance phenomena, Fano resonance, emerges. The tuning of Fano resonance can be observed by engineering the structural parameters of the device. The sensing principle is analyzed through the numerical investigation FDTD (Finite difference in time-domain) method. This sensor's performance is quantified using sensitivity. The proposed sensor reports high sensitivity (S = 1250 nm/RIU) with an ultra-narrow line width of 10 nm. The study opens a means for the designing of on-chip optical sensors that will be viable in bio-sensing and chemical sensing. [ABSTRACT FROM AUTHOR]

For creep and shrinkage investigations, relatively small cylindrical specimens are generally exposed to constant climatic conditions. The derived mainly empirical prediction models are used for the calculation of large engineering structures with massive cross‐sections. In this paper, the expected values of the material models according to fib Model Code 2010 and Eurocode 2 are compared with monitoring data, which were acquired over a period of more than 12 years during a structural health monitoring of a large viaduct. It was found that in addition to the measured continuous increase in the viscous deformations, seasonal fluctuations due to climatic influences could also be detected. The numerical calculations show that the material models differ significantly in their magnitude and time course of the predicted viscous concrete deformations. In comparison with the monitoring data, a good agreement was achieved when using the material models according to Eurocode 2. The models of the fib Model Code 2010, on the other hand, underestimated the deformations of the massive bridge girder. [ABSTRACT FROM AUTHOR]

The strength of filled bolt holes of composites is an important parameter in developing the bearing bypass envelope curves for bolted joint structures in engineering design. This paper presents the procedures of tensile failure strengths and damage for a laminate with a filled bolt hole. Tests of two different cases, open‐hole tension (OHT) and filled‐hole tension (FHT), were performed and repeated seven times, respectively. A new type of virtual testing based on the LaRC05 criteria coupling with XFEM crack technique was developed to predict and analyze the crack initiation and early propagation around the bolt hole in the laminates. Two analytical methods were also adopted to predict the residual strength for a laminate after drilling. The results show that the thinner sample would present a higher strength with the same material system. It is also shown that the virtual test can well capture the failure modes, revealing that the 0° fiber has a natural function of crack arrest, the 90° layers that are the fracture pioneers with matrix tensile failure trigger the fiber breakage of 0° layers, and the failure of 45° layers occurs at the last. Additionally, an interesting phenomenon is observed that the initial failure around the filled hole edge does not affect the structural stiffness. Finally, a good agreement is achieved among the experimental, analytical and numerical results. It suggests that the results could provide a valuable guidance for the design of multi‐bolted joint structure. [ABSTRACT FROM AUTHOR]

In this paper, the seismic design factors for uncoupled composite plate shear walls/concrete filled (C-PSW/CF), a.k.a. SpeedCore, are verified by conducting a study using FEMA methodology. These are the seismic response modification factor, R, the deflection amplification factor, Cd, and the overstrength factor, Ωo; and their values for C-PSW/CF are specified as 6.5, 5.5, and 2.5, respectively. A study was needed, as these factors for uncoupled C-PSW/CFs, included in ASCE 7 since as far back as its 2000 edition, were chosen solely based on the seismic performance of similar structural systems and engineering judgment of the committee members. For this study, four archetypes with planar walls and three archetypes with C-shaped C-PSW/CF walls were chosen. Two different damage measures (DM) were chosen for this study; namely, 3% and 5% maximum interstory drifts. Based on FEMA methodology, all archetypes satisfied the specified performance requirement considering a "good" rating for total system collapse uncertainty (βTOT). [ABSTRACT FROM AUTHOR]

Shock tubes can carry out dynamic mechanical impact tests on civil engineering structures. The current shock tubes mostly use an explosion with aggregate charge to obtain shock waves. Limited effort has been made to study the overpressure field in shock tubes with multi-point initiation. In this paper, the overpressure fields in a shock tube under the conditions of single-point initiation, multi-point simultaneous initiation, and multi-point delayed initiation have been analyzed by combining experiments and numerical simulations. The numerical results match well with the experimental data, which indicates that the computational model and method used can accurately simulate the blast flow field in a shock tube. For the same charge mass, the peak overpressure at the exit of the shock tube with the multi-point simultaneous initiation is smaller than that with single-point initiation. As the shock waves are focused on the wall, the maximum overpressure on the wall of the explosion chamber near the explosion zone is not reduced. The maximum overpressure on the wall of the explosion chamber can be effectively reduced by a six-point delayed initiation. When the interval time is less than 10 ms, the peak overpressure at the nozzle outlet decreases linearly with the interval of the explosion. When the interval time is greater than 10 ms, the overpressure peak remains unchanged. [ABSTRACT FROM AUTHOR]

This paper presents a framework that can transform reconfigurable structures into systems with continuous equilibrium. The method involves adding optimized springs that counteract gravity to achieve a system with a nearly flat potential energy curve. The resulting structures can move or reconfigure effortlessly through their kinematic paths and remain stable in all configurations. Remarkably, our framework can design systems that maintain continuous equilibrium during reorientation, so that a system maintains a nearly flat potential energy curve even when it is rotated with respect to a global reference frame. This ability to reorient while maintaining continuous equilibrium greatly enhances the versatility of deployable and reconfigurable structures by ensuring they remain efficient and stable for use in different scenarios. We apply our framework to several planar four-bar linkages and explore how spring placement, spring types, and system kinematics affect the optimized potential energy curves. Next, we show the generality of our method with more complex linkage systems that carry external masses and with a three-dimensional origami-inspired deployable structure. Finally, we adopt a traditional structural engineering approach to give insight on practical issues related to the stiffness, reduced actuation forces, and locking of continuous equilibrium systems. Physical prototypes support the computational results and demonstrate the effectiveness of our method. The framework introduced in this work enables the stable, and efficient actuation of reconfigurable structures under gravity, regardless of their global orientation. These principles have the potential to revolutionize the design of robotic limbs, retractable roofs, furniture, consumer products, vehicle systems, and more. [ABSTRACT FROM AUTHOR]

Highlights: This review discusses the roles of MXenes in different positions/layers in perovskite solar cells. The issues in different layers/interfaces and their addressal with the incorporations of MXenes in perovskite solar cells are elaborately discussed. With an excellent power conversion efficiency of 25.7%, closer to the Shockley–Queisser limit, perovskite solar cells (PSCs) have become a strong candidate for a next-generation energy harvester. However, the lack of stability and reliability in PSCs remained challenging for commercialization. Strategies, such as interfacial and structural engineering, have a more critical influence on enhanced performance. MXenes, two-dimensional materials, have emerged as promising materials in solar cell applications due to their metallic electrical conductivity, high carrier mobility, excellent optical transparency, wide tunable work function, and superior mechanical properties. Owing to different choices of transition elements and surface-terminating functional groups, MXenes possess the feature of tuning the work function, which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in PSCs. Furthermore, adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths, leading to enhanced conductivity and operational stability of PSCs. This review paper aims to provide an overview of the applications of MXenes as components, classified according to their roles as additives (into the perovskite absorber layer, charge transport layers, and electrodes) and themselves alone or as interfacial layers, and their significant importance in PSCs in terms of device performance and stability. Lastly, we discuss the present research status and future directions toward its use in PSCs. [ABSTRACT FROM AUTHOR]

Purpose: In this paper, the main factors influencing the structure stiffness will be analyzed by studying the tangent stiffness matrix based on different requirement in engineering practice. The authors can obtain the deformation of three-bar tensegrity basic unit in different load, and gain the primary factor by comparing the deformation, which will provide reference to concrete structure design in the engineering. Design/methodology/approach: The mathematical model of tensegrity structure was built by establishing generalized node coordinates and connective matrix. Three main factors that affect the structure deformation can be obtained by analyzing the stiffness matrix, which is preload, Young's modulus, and cross-sectional area, the thinking of deformation also be sorted out. The deformation analysis of the concrete structure is carried out, and it is concluded that increasing the cross-sectional area can quickly improve the stiffness of the structure, which provides a reference for the structural variable stiffness design in practical engineering. Findings: (1) When the axial external force is applied to the structure, the torsion-angle deformation of the structure is the largest, and the radial deformation of the structure is the smallest. (2) The structure stiffness can be rapidly enhanced by increasing the cross-sectional area. But the cross-sectional area can't be increased indefinitely. Because the mass will be increased once increasing the cross-sectional area, which will destroy the structure of the advantages of light weight in engineering practice. Originality/value: The deformation analysis of the concrete structure is carried out, and it is concluded that increasing the cross-sectional area can quickly improve the stiffness of the structure, which provides a reference for the structural variable stiffness design in practical engineering. [ABSTRACT FROM AUTHOR]

Early detection of damage is necessary for the safe and reliable use of civil engineering structures made of concrete. Recently, the identification of micro-cracks in concrete has become an area of growing interest, especially when it comes to using wave-based techniques. In this paper, a non-destructive testing approach for the characterization of the fracture process was presented. Experimental tests were performed on concrete beams subjected to mechanical degradation in a 3-point bending test. Ultrasonic waves were registered on a specimen surface by piezoelectric transducers located at several points. Then, the signals were processed taking advantage of wave scattering due to micro-crack disturbances. For early-stage damage detection, coda wave interferometry was used. The novelty of the work concerns the application of the complex decorrelation matrix and the moving reference trace approach for better distinguishment of sensors located in different parts of a crack zone. To enhance coda wave-based damage identification results, optical imaging of crack development was performed by means of digital image correlation measurement. The results obtained showed that the coda wave interferometry technique can be successfully used as a quantitative measure of changes in the structure of concrete. The results also indicated that the course of decorrelation coefficient curves enabled the identification of three stages during degradation, and it depended on the location of acquisition points versus the crack zone. [ABSTRACT FROM AUTHOR]

Laboratory research of wood–CFRP (carbon fiber reinforced polymer) structural elements, especially beams, is a scientific issue undertaken by many scientists. Research is often complemented with numerical analysis with the use of complex finite element method (FEM) models. Modern FEM software offers models that can reproduce such properties and phenomena as orthotropy and plasticity of wood and CFRP, delamination and mechanical behavior of adhesive layers, and damage of a strengthened element. The author of the paper reproduces numerical laboratory research of a four-point bending test of a glulam beam strengthened with CFRP tape. The main goal of the numerical research is an analysis of how the complexity of the FEM model influences the results of calculations, especially stress, deflection, and bearing capacity of the glulam beam. In some cases, a simpler model can be satisfactory, especially for a structural engineer, who takes into account serviceability limit states (permissible deflection of a structural member) and assumes that stress should not exceed the yield stress of timber. [ABSTRACT FROM AUTHOR]