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In the final manuscript [[33]], presented as a communication, the author indicates that unmanned aircraft systems (UASs), commonly referred to as drones, are an emerging technology that has changed the way that many industries conduct business. When used on a state-by-state basis, the normalized UAS adoption index shows that there are regional differences in UAS adoption, with western and eastern states having higher UAS adoption rates and central states having significantly lower UAS adoption rates. The aim of this second I Eng i Special Issue is to collect experimental and theoretical re-search relating to engineering science and technology. Telecommunication companies collect a deluge of subscriber data without retrieving substantial information. [Extracted from the article]

The time-modulated active medium with linear independent frequency conversion method has been demonstrated to enable wave orientation and reconstruction. However, due to the symmetric scattering field, this technique requires intricate microcircuit designs. To overcome this limitation, this paper proposes a tunable piezoelectric metasurface based on acoustic black holes (ABHs) to redirect flexural wave reflections. The system can convert an incident flexural wave into a reflected wave of any direction and frequency. This is accomplished through the linear time modulation of the sensing signal, which breaks the constraints of Snell's law inherent in traditional designs and is insensitive to the incident amplitude. The coupling of the ABH damping system with a linear independent frequency conversion mechanism allows for the conversion of an incident flexural wave into a reflected wave in any direction and frequency while also eliminating the influence of second harmonic reflection on the wave field and simplifying the time modulation circuit. In addition, this paper demonstrates arbitrary angle reflection, focusing, beam splitting, and frequency conversion of the incident wave. By improving the flexibility of elastic wave manipulation, this paper introduces a new approach for active control of elastic waves and provides a design method that can be employed in a variety of applications ranging from vibration protection of engineering structures to vibration sensing and evaluation. [ABSTRACT FROM AUTHOR]

The article discusses the importance of reproducibility in academic research, particularly in the field of structural engineering. It acknowledges the challenges in achieving reproducibility, such as data storage and computing requirements, as well as proprietary issues. The authors argue for the development of a reproducibility policy in the Journal of Structural Engineering and the Journal of Bridge Engineering, taking into account the nature and culture of research in these subdisciplines. They propose a classification system that emphasizes the availability of data and metadata, and encourage authors to go beyond data availability by making models and other materials accessible. To incentivize research and data availability, the journals will provide a visible recognition badge for papers with open data/models/codes and may consider special recognition for these papers. The authors also outline the review process for data-verified papers, which involves three associate editors verifying the availability and representativeness of the data. [Extracted from the article]

She holds a B.Eng. in building engineering from Tongji University (2001), a M.S. in civil engineering from the University of Massachusetts (2005), and a Ph.D. in geotechnical engineering from the Georgia Institute of Technology (2010). Dr. Tan's areas of specialization include deep excavation and tunnelling, foundation engineering, forensic geotechnical engineering, and engineering failures associated with climate change. He received his B.Eng. in building engineering from Tongji University (1999), M.Eng. in Geotechnical Engineering from Tongji University (2002), and Ph.D. in civil engineering from the University of Massachusetts (2005). [Extracted from the article]

Paper is an ideal substrate for manufacturing flexible electrodes because of its lightweight, inherent mechanical flexibility, and unique structure. However, the traditional bottom-up method of manufacturing paper-based electrode is time-consuming and the active material is easy to fall off. Here, we report a polypyrrole-deposited conductive paper (PCP), which is fabricated by chemical treatment, mechanical compression, and chemical polymerization of natural wood. The post densification process eliminates the vertical arrangement of wood cell cavities, and the formed wood fiber/multi-walled carbon nanotubes hybrid conductive network has high flexibility. The further deposited polypyrrole (PPy) conductive layer can effectively boost the ion transport between electrode/electrolyte interface and increase the active center of interface reaction. Based on the well-designed electrode structure and good interfacial reaction kinetics, the resulting PCP with a PPy mass loading of only 2.4 mg·cm−2 indicates a high areal capacitance of 275.8 mF cm−2 at 20 mV·s−1 and good cycling stability. All-solid-state symmetric supercapacitor exhibits capacitance of 308.3 mF·cm−2. This structure and interface design concept show a promising method for preparing high-performance and scalable biomass-based flexible electronic devices. • A novel structure and interface design concept was proposed. • The PCP electrode has high specific/areal capacitance. • The supercapacitor shows excellent cycling performance of 90.1%. [ABSTRACT FROM AUTHOR]

Periodic structures are a type of metamaterial in which the physical properties depend not only on the details of the unit cell but also on how unit cells are arranged and interact with each other. In conventional engineering structures, each unit cell interacts with adjacent cells. Methods developed for vibrational and wave propagation analysis in periodic engineering structures consider only nearest-neighbor interactions. The dispersion curves of such systems, in which only adjacent cells interact, have been extensively studied. Metamaterial properties depend on the interactions of a unit cell with other cells. Further interactions, and specifically, interactions beyond the closest neighbors, imply a more complex band structure and wave behavior. In this paper, an example class of such structures, in which electrostatic forces are the driving force, has been investigated. In this paper, properties affecting these periodic structures, such as elastic forces, have been investigated. An attractive property of such structures is that the band structures of such metamaterials can be tuned by changing electric voltages. [ABSTRACT FROM AUTHOR]

WH‐Überseequartier in Hamburg – civil engineering structures and foundations In the HafenCity district of Hamburg, Germany, the new WH‐Überseequartier is nearing its completion. Unibail‐Rodamco‐Westfield is the company behind the project as investor, developer and operator of the new district, which has a total gross floor area of 419.000 square meters and consists of 14 buildings based on designs from numerous architectural firms. This paper describes the challenges of planning and implementing the various civil engineering structures required in the district, from the construction pits in combination with the subway station located in the middle of the construction site to the necessary partial replacement of the quay walls at Chicagokai and the foundations of the new buildings and landscape architecture. A second paper, describing the structures of the buildings from a design and construction perspective, will follow. [ABSTRACT FROM AUTHOR]

Standards for the design of bridges, buildings and other infrastructure specify design loads for climatic hazards such as temperature, snow, wind, and floods based on return periods presented in maps or tables that account for regional differences. These design loads were developed from statistical analyses of historical hazard data under the assumption that the past is representative of the future. Climate change may affect the frequencies and intensities of environmental hazards which, depending on regional variations, raises questions as to whether structures designed to current specifications will meet minimum safety standards over their future service lives. This paper critically appraises issues related to using historical hazard data for future designs. It reviews basic principles of uniform reliability, that modern design codes use as the basis for ensuring minimum levels of safety, describing the relationship between hazard return periods, structural reliability, risk and the maximum loads expected within a structure's service life. Simple examples involving wind effects on structures demonstrate how to calibrate structural design hazard maps for climate-related extreme events to meet the minimum standards of safety implied in current specifications. The paper also introduces a possible practical approach to account for climate change when designing new structures and assessing the safety of existing facilities. [ABSTRACT FROM AUTHOR]

Despite the complex punching shear behavior of reinforced concrete slabs have been comprehensively addressed in the literature, it is further essential to develop a universal design model comprising high accuracy and the simplicity for design practicability, adaptable to diverse conditions encountered in practice. Artificial intelligence applications, artificial neural networks (ANN), and more recently, various machine learning (ML) and deep learning (DL) techniques veer off in a new direction in structural engineering context with improved accuracy and efficiency. The paper begins with the assessment of the capabilities of various artificial intelligence applications in predicting the punching shear strength of slab-column connections without shear reinforcement through the extensive database using 650 punching shear experiments from the literature. Critical parameters influencing the punching shear strength as well as the precision of the current code provisions in predicting this feature were then thoroughly examined in the paper. The results shown in this paper validated the competency of artificial intelligence applications in predicting the punching shear strength of such connections with increased accuracy and improved simplicity in practical terms. The proposed models utilizing the artificial intelligence applications encourage the ultimate rehabilitation policies to be proposed and improved code provisions to be developed for contemporary structures. [ABSTRACT FROM AUTHOR]

The γ‐procedure for calculation of partially composite beams consisting of flexibly jointed cross‐section with any number of sub‐elements: general method The so‐called γ‐procedure is essentially important for the calculation of partially composite beams consisting of flexibly jointed cross‐section. In this paper, the basic principle and the exact solution of the γ‐procedure are described. In the German and European standards of timber structures, partially composite beams with a maximum number of three sub‐elements can be calculated. This paper proposed a method that can extend the calculation of partially composite beams with any number of sub‐elements. [ABSTRACT FROM AUTHOR]

The field of (practical) data-driven approaches that utilize the vibration signature of target systems for developing mathematical models (for computational purposes, control, or anomaly detection for structural health monitoring) is still an active research area, despite the fact that several powerful system identification techniques have been developed in the system dynamics field to analyze such measurements. However, there is still a paucity of comprehensive experimental studies that investigate the range of validity of such identification techniques, particularly those applicable to realistic situations encountered in the structural engineering field, with the focus on detecting, quantifying, locating, and classifying observed changes, especially when there are significant inherent nonlinearities in the reference (undamaged) complex target structure, and where there are unavoidable sources of errors and uncertainties in the measurements and the attendant data analysis procedures. The research team constructed a well-instrumented, reconfigurable test apparatus (resembling a tall building) that allows the introduction of quantifiable levels of composite changes at various locations, orientations, and types of linear and/or nonlinear changes, with the aim of investigating a subset of the aforementioned challenges facing researchers who are interested in assessing the utility of some practical system identification approaches. The primary focus of the identification approach is on a decomposition procedure that is ideally suited for certain types of structures that possess some topological features that can be exploited to enhance the detectability of small changes. A companion paper provides a detailed description of the testbed features and its instrumentation. The present paper focuses on the analysis of some of the very extensive data sets that were created to study the usefulness of some practical dimensionless probabilistic measures that not only provide normalized change indices but also simultaneously attach a confidence level to each of these indices. [ABSTRACT FROM AUTHOR]

University scientific research ability is an important indicator to express the strength of universities. In this paper, the evaluation of university scientific research ability is investigated based on the output of sci-tech papers. Four university alliances from North America, UK, Australia, and China, are selected as the case study of the university scientific research evaluation. Data coming from Thomson Reuters InCites are collected to support the evaluation. The work has contributed new framework to the issue of university scientific research ability evaluation. At first, we have established a hierarchical structure to show the factors that impact the evaluation of university scientific research ability. Then, a new MCDM method called D-AHP model is used to implement the evaluation and ranking of different university alliances, in which a data-driven approach is proposed to automatically generate the D numbers preference relations. Next, a sensitivity analysis has been given to show the impact of weights of factors and sub-factors on the evaluation result. At last, the results obtained by using different methods are compared and discussed to verify the effectiveness and reasonability of this study, and some suggestions are given to promote China’s scientific research ability. [ABSTRACT FROM AUTHOR]

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]

Uncertainty propagation of the frequency response function is crucial for vibration problems such as model calibration, and the probability assessment is another indispensable item in structural optimization. Considering only one of them will inevitably lead to a lack of uncertain knowledge of practical engineering structures. However, it is still challenging to evaluate the system response bounds and probability characteristics simultaneously and maximally reduce the computational cost. This paper focuses on the frequency response function involving correlated uncertainties and proposes a novel uncertainty propagation and probability assessment method. First, a convex model was established to quantify the correlated uncertainty parameters, and then, the Chebyshev polynomial function was developed as the surrogate model to efficiently quantify the uncertainty propagation from uncertainty parameters to system response. Subsequently, the novel normalized and coordinated transformation combined the uncertainty propagation method, making the uncertainty system response easy to assess. Note that the response value at the interpolation point can be employed as the input of probability assessment. One can also estimate the probability characteristics at different frequency positions during the construction of the surrogate model. Finally, two numerical examples were presented to demonstrate the effectiveness and cheaper computation by a discrete system and a continuous system, respectively. Results indicate that the proposed method can be conveniently and accurately applied to assess the bounds and probability characteristics of frequency response function involving correlated uncertainties. [ABSTRACT FROM AUTHOR]

Rock strength parameters such as uniaxial compressive strength and modulus of elasticity are crucial parameters in designing rock engineering structures. Owing to the importance of the aforementioned parameters, in this paper, image processing technique is coupled with artificial neural network (ANN) method for assessing the uniaxial compressive strength and modulus of elasticity of sandstones. For this reason, 102 core sandstone samples were prepared. Subsequently petrographic analyses and imaging operation for 102 images were performed. Principal component analysis was then conducted for feature reduction purposes. At last, an ANN model, which received its input data from image processing technique, was constructed for assessing the UCS and E of sandstone samples. Overall, the best performance of the network was obtained when 10 hidden nodes were used. The correlation coefficient (R) values of 0.9722 and 0.97062 for UCS and E, respectively, suggest the feasibility of the proposed model. [ABSTRACT FROM AUTHOR]

Summary: Structural performance assessment is a critical stage in the health monitoring for the maintenance and risk management of engineering structures, in which the interstory drift is a key indicator. In this paper, a robust adaptive Kalman filter is proposed for an interstory drift estimation problem to show the health condition of steel structures in the case that the statistics or internal dynamics describing the signals and measurements are not known precisely. More precisely, we build an adaptive current Jerk model (ACJM) where the model parameters are updated in each time step to presuppose the statistics characterization of the steel dynamic, while the unknown measurement noise covariance is adapted based on a fixed‐lag innovation with respect to measurements. Moreover, a robust adaptive Kalman filter is designed for the modelling uncertainties in each time increment by solving a minimax game: one player tries to select an "actual" model far from the proposed ACJM with an exponential decay tolerance, while its "hostile" player, namely, the optimum filter, is designed by minimizing the estimation error according to the selected "actual" model. Finally, some simulation and experimental results show the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In the engineering structures using circular steel tube (CST), the eccentric loading of CST members often occurs due to installation error and structural form. Existing research mainly focuses on the bearing resistance of circular steel pipes under the condition of eccentricity at one end. In practical application, both ends of CST members also may be eccentric. And with the increase in eccentricity, material yielding may occur prior to flexural buckling. So far, it's lack of reports about the mechanical behavior of CST members subjected to eccentric loading at both ends and the boundary between material yielding and flexural buckling. This paper presents experimental, numerical and theoretical studies on bearing resistance of thin-walled circular steel tube with slenderness ratio of 30, 40 and 50, subjected to eccentric loading at one end and both ends, respectively. The study reveals a significant discrepancy in the prediction of bearing resistance for circular tubes subjected to eccentric loading at both ends according to existing design codes. Considering the synthesis of bending moment and deflection caused by eccentric loading at both ends, the calculation method of the bearing resistance based on flexural buckling of CST is established, which enhances the prediction accuracy of test verification. In addition, a theoretical boundary between the two failure modes appearing in CST members under eccentric loading at one and both end(s) - flexural buckling and reaching the material yielding strength - was established as dominated by the slenderness ratio and loading eccentricity. [ABSTRACT FROM AUTHOR]

This paper provides an insight that opens up systemic flaws with regulatory bodies and a considerable blind spot in professional indemnity insurance. This is an eye-opening analysis of an industry that is closely tied to building surveyors, structural engineers, valuers, architects and — by extension — lawyers. [ABSTRACT FROM AUTHOR]

A large number of experiments show that composite materials usually show different modulus properties in tension and compression (bi-modulus). However, for actual composite engineering structures, especially complex models, the numerical simulation calculation is usually based on a single modulus. In order to consider the different modulus characteristics of composite materials in tension and compression, researchers put forward simplified constitutive models of dual-modulus materials. However, these constitutive models have not been verified by a large number of experiments, especially by complex models. In this paper, the GWFMM model is simplified and used to analyze complex structures with different modulus in tension and compression. The experimental results of stiffened plate show that the improved GWFMM model can be used to analyze different modulus of tension and compression of complex stiffened structures. In addition, the influence of elastic modulus ratio in tension and compression under different experimental load conditions is further explored, and the influence law of bending and torsion on structures with bi-modulus is discussed. The relevant conclusions provide reference for the design and optimization of full-scale composite structures in marine engineering. [ABSTRACT FROM AUTHOR]

Architected materials are a new class of materials that interlink practices in architecture and structural engineering to produce materials by conjugation of several simple materials through the interplay between geometry and material properties. Tensegrity structures are composed of struts and cables held in a state of self-stress. With a high strength-to-weight ratio, they provide opportunities for deployable and transportable bridges. Although tensegrity structures are indeterminate, cable damage is challenging to predict and detect a priori, which is aided by a resilient architected material segment as a structural health indicator. The technology of 3D printing complements the development of architected material. Computational studies have shown the effect of coordination number and cross-linking density on the stretch behavior of polymer networks for microscopic deformation scale. This paper presents the relationship between various parameters of multilayered randomized architected material (MLRAM) and its tensile behavior. The randomization of link orientation is to address the unknown direction of the critical force in the strut. A computational model calibrated through experimental testing was developed that mimics the tensile behavior of MLRAM. Using this model, the variation in the tensile behavior in terms of peak tensile capacity and postpeak behavior of MLRAM can be studied for various geometries with specific parameters. From the study, it is observed that the tensile capacity and stiffness of the MLRAM increase with a higher coordination number. The recent advancement of additive manufacturing and 3D printing have provided researchers with the scope to study the feasibility of many difficult geometries and its properties. This is one such study that develops and investigates the tensile properties of a newly developed multilayered randomized architected material (MLRAM). The tensile properties were determined experimentally for centimeter-scale 3D-printed models and a computational model was proposed to replicate the behavior in the linear static region. This novel study provides a preliminary idea of a new concept of architected material that can be extended to a three-dimensional concept in the future. First, the model helps researchers investigate various geometry and design materials with properties as required for specific applications. This proposed MLRAM extended into a three-dimensional material also has the potential to act as visual damage detection indicators that can be incorporated in highly redundant structural systems such as tensegrity structures. [ABSTRACT FROM AUTHOR]

This paper investigates the formation, annihilation, and evolution mechanisms of potential energy wells in nonlinear energy sink systems. The nonlinear energy sink system is composed of multiple inner and outer magnets. Two multi-magnet energy sink (MES) architectures are designed: a single-magnet vibrator and a double-magnet vibrator. Multi-stable (bi-, tri-, quad-, penta-, hexa-, and hepta-stable) mechanisms are elaborated by the Poincaré section and bifurcation diagram concerning the magnet length, the link length, and the MES configuration. The results show that the change in the internal structural parameters of the MES system will generate different types of bifurcations (i.e., saddle-node, subcritical, and super pitchfork bifurcations) and phase trajectories and have rich nonlinear response behaviors in the low frequency and wide frequency range, which can be used for damping and vibration reduction of engineering structures, vibration control, and energy source of the microgrid. [ABSTRACT FROM AUTHOR]

The primary objective of this paper is to examine the free vibration behaviors of functionally graded nanobeams with porosity while considering nonlocal parameters. The nanobeams are built of functionally graded materials, having material features that change smoothly over the beam's thickness. To illustrate how porosity is distributed throughout the body of the beams, four different forms of porosity distribution are taken into consideration. Eringen's nonlocal parameter elasticity theory and Hamilton's principle are used to establish the governing equations of the motion of the functionally graded porous nanobeams. Then, the closed-form solution of Navier is used to solve the eigenvalue problems to find the frequencies of the functionally graded porous nanobeams. A comprehensive parametric study is also carried out to demonstrate the influence of geometric parameters, material gradient index, and nonlocal parameters on low- and high-frequency vibration behaviors of the functionally graded porous nanobeams. The results of the vibration of the functionally graded porous nanobeams undergoing the low- and high-frequency conditions can serve as benchmarks for applications of such structures in engineering and for future work. [ABSTRACT FROM AUTHOR]

Assessment and retrofitting of riveted lattice girders in metal roof structures Metal structures from the 19th and early 20th centuries, such as factories, train sheds and market halls, are a valuable and useful heritage. Preserving these structures by maintaining or adapting their use is of economic, ecological, and cultural interest. In this endeavour, accurately assessing their load capacity by calculation is a challenge. In France, riveted lattice girders are widely used in roof structures dating from 1850–1930. Numerically, they present stability problems often leading to preventive strengthening measures. This paper draws on the study of these structural components to explore a novel holistic assessment method that combines structural engineering, construction history and heritage conservation to provide a robust basis for the design of sensitive and targeted structural interventions. This approach could be extended to iron and steel structures of the 19th and early 20th centuries, and broadly to most types of existing structures. [ABSTRACT FROM AUTHOR]

On the global warming potential (GWP) of centric loaded columns in structural engineering The advancing climate change and the change of boundary conditions regarding the planning process of buildings are influencing the building industry in its fundamental principles. A "business as usual" is irresponsible in view of the proclaimed goals of the German government regarding climate neutrality in 2045. This paper is intended as a step towards the necessary sensitization regarding a more sustainable structural design using the example of centric loaded structural columns in structural engineering. For the selected materials timber, steel and reinforced concrete the main factors influencing the GWP are discussed and compared on the basis of functional equivalence. The aim of the comparison is to determine the sensitivity of individual parameters with regard to the global warming potential (GWP) of structural columns and to support more ecological structural design. [ABSTRACT FROM AUTHOR]

In this article, the practical issues connected with guided wave measurement are studied: (1) the influence of gluing of PZT plate actuators (NAC2013) on generated elastic wave propagation, (2) the repeatability of PZT transducers attachment, and (3) the assessment of the possibility of comparing the results of Laser Doppler Vibrometry (LDV) measurement performed on different 2D samples. The consideration of these questions is crucial in the context of the assessment of the possibility of the application of the guided wave phenomenon to structural health-monitoring systems, e.g., in civil engineering. In the examination, laboratory tests on the web of steel I-section specimens were conducted. The size and shape of the specimens were developed in such a way that they were similar to the elements typically used in civil engineering structures. It was proved that the highest amplitude of the generated wave was obtained when the exciters were glued using wax. The repeatability and durability of this connection type were the weakest. Due to this reason, it was not suitable for practical use outside the laboratory. The permanent glue application gave a stable connection between the exciter and the specimen, but the generated signal had the lowest amplitude. In the paper, the new procedure dedicated to objective analysis and comparison of the elastic waves propagating on the surface of different specimens was proposed. In this procedure, the genetic algorithms help with the determination of a new coordinate system, in which the assessment of the quality of wave propagation in different directions is possible. [ABSTRACT FROM AUTHOR]

Multi-layer complex structures are widely used in large-scale engineering structures because of their diverse combinations of properties and excellent overall performance. However, multi-layer complex structures are prone to interlaminar debonding damage during use. Therefore, it is necessary to monitor debonding damage in engineering applications to determine structural integrity. In this paper, a damage information extraction method with ladder feature mining for Lamb waves is proposed. The method is able to optimize and screen effective damage information through ladder-type damage extraction. It is suitable for evaluating the severity of debonding damage in aluminum-foamed silicone rubber, a novel multi-layer complex structure. The proposed method contains ladder feature mining stages of damage information selection and damage feature fusion, realizing a multi-level damage information extraction process from coarse to fine. The results show that the accuracy of damage severity assessment by the damage information extraction method with ladder feature mining is improved by more than 5% compared to other methods. The effectiveness and accuracy of the method in assessing the damage severity of multi-layer complex structures are demonstrated, providing a new perspective and solution for damage monitoring of multi-layer complex structures. [ABSTRACT FROM AUTHOR]

Structural engineers are often required to draw two-dimensional engineering sketches for quick structural analysis, either by hand calculation or using analysis software. However, calculation by hand is slow and error-prone, and the manual conversion of a hand-drawn sketch into a virtual model is tedious and time-consuming. This paper presents a complete and autonomous framework for converting a hand-drawn engineering sketch into an analyzed structural model using a camera and computer vision. In this framework, a computer vision object detection stage initially extracts information about the raw features in the image of the beam diagram. Next, a computer vision number-reading model transcribes any handwritten numerals appearing in the image. Then, feature association models are applied to characterize the relationships among the detected features in order to build a comprehensive structural model. Finally, the structural model generated is analyzed using OpenSees. In the system presented, the object detection model achieves a mean average precision of 99.1%, the number-reading model achieves an accuracy of 99.0%, and the models in the feature association stage achieve accuracies ranging from 95.1% to 99.5%. Overall, the tool analyzes 45.0% of images entirely correctly and the remaining 55.0% of images partially correctly. The proposed framework holds promise for other types of structural sketches, such as trusses and frames. Moreover, it can be a valuable tool for structural engineers that is capable of improving the efficiency, safety, and sustainability of future construction projects. [ABSTRACT FROM AUTHOR]

Predicting the moment-rotation response parameters of semirigid steel connections can be challenging given the many components contributing to the connection's elastic and plastic deformations. This is the case for the popular flush endplate beam-to-column connections (FEPCs). The literature has highlighted the limitations of current analytical, mechanical, and traditional empirical models in providing accurate predictions of the FEPCs' moment-rotation response. Considering this limitation, machine-learning methods have gained wide attention recently in structural engineering applications to address problems associated with complex structural deformation and damage phenomena. To that end, the superior nonlinearity of artificial neural networks (ANN) is employed herein to predict the response characteristics of FEPCs. A large data set of about 200 specimens, collected from past experimental programs, is utilized to train the ANN for predicting the bilinear response of FEPCs including strain hardening. The paper describes the deduction of the response parameters from test data using data fitting, the determination of significant geometric, material, and layout features, the ANN architecture and algorithms, and the accuracy metrics of the new model. The Shapley algorithm is used to explain the inner workings of the model. A computer tool as well as a descriptive guide to the mathematical construction of the ANN are provided to aid with model implementation in practice. [ABSTRACT FROM AUTHOR]

The traditional approach to formulating building codes often is slow and labor-intensive, and may struggle to keep pace with the rapid evolution of technology and domain findings. Overcoming such challenges necessitates a methodology that streamlines the modernization of codal provisions. This paper proposes a machine learning (ML) approach to append a variety of codal provisions, including those of empirical, statistical, and theoretical natures. In this approach, a codal provision (i.e., equation) is analyzed to trace its properties (e.g., engineering intuition and causal logic). Then a ML model is tailored to preserve the same properties and satisfy a collection of similarity and performance measures until declared equivalent to the provision at hand. The resulting ML model harnesses the predictive capabilities of ML while arriving at predictions similar to the codal provision used to train the ML model, and hence it becomes possible to use in lieu of the codal expression. This approach was examined successfully for seven structural engineering phenomena contained within various building codes, including those in North America and Australia. The findings suggest that the proposed approach could lay the groundwork for implementing ML in the development of future building codes. [ABSTRACT FROM AUTHOR]

Numerous studies revealed optimization techniques' applicability in minimizing the costs of reinforced concrete buildings. However, the existing literature has narrowly focused on optimizing buildings with a single function, such as residential or office buildings, hindering the generalization of the results. This paper aims to bridge the gap between optimization and structural engineering by obtaining the minimum-cost design of flat slab buildings with different intended functions. In this context, the optimal designs of 120 alternatives were obtained, considering various spans (4–8 m), live loads (2–10 kPa), and concrete compressive strength (25–40 MPa). The optimization was executed using the evolutionary algorithm provided in Microsoft Excel's Solver tool. The optimization model permits the utilization of drop panels to resist punching stresses developed from the slab-column interaction. The objective function is the cost of materials and labor involved in constructing floors and columns. The decision variables are the floor dimensions and column configurations in dimensions and reinforcement. The structural constraints were applied per the Egyptian design code (ECP203-2020). Eventually, guidelines were developed to help the designers choose the economic floor system and quantities of materials based on the building's intended function. [ABSTRACT FROM AUTHOR]

This paper proposes a local resonance-type pentagonal phononic crystal beam structure for practical engineering applications to achieve better vibration and noise reduction. The energy band, transmission curve, and displacement field corresponding to the vibration modes of the structure are calculated based on the finite element method and Bloch-Floquet theorem. Furthermore, an analysis is conducted to understand the mechanism behind the generation of bandgaps. The numerical analysis indicates that the pentagonal unit oscillator creates a low-frequency bandgap between 60–70 Hz and 107–130 Hz. Additionally, the pentagonal phononic crystal double-layer beam structure exhibits excellent vibration damping, whereas the single-layer beam has poor vibration damping. The article comparatively analyzes the effects of different parameters on the bandgap range and transmission loss of a pentagonal phononic crystal beam. For instance, increasing the thickness of the lead layer leads to an increase in the width of the bandgap. Similarly, increasing the thickness of the rubber layer, intermediate plate, and total thickness of the phononic crystals results in a bandgap at lower frequencies. By adjusting the parameters, the beam can be optimized for practical engineering purposes. [ABSTRACT FROM AUTHOR]

An implicit limit state function is predicted with a support vector machine (SVM) for reliability analysis of engineering structures to reduce the number of finite element analyses. The accuracy and predictability of the SVM method are reduced considerably by noise in data. In this paper, density-based spatial clustering of applications with noise (DBSCAN) is applied to reduce the noise in training samples for SVM regression. Then, the SVM model is linked with Monte Carlo simulation (MCS) to find out the reliability of the engineering structures. Four different examples of static and dynamic problems are solved to show acceptability and efficiency of the proposed method. It is observed that the proposed method is suitable for a smaller number of performance function calls. Direct MCS, artificial neural network-based MCS and response surface methods have been used to examine the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

This paper intends to investigate the effect of tunnelling on the response of a framed building on different types of foundations with the help of shake table test. For the test, effect of utility tunnel on response of scaled prototype steel building has been determined with the help of accelerometer mounted at different floors. For experimental tests, three types of foundation (isolated foundation, mat foundation, and pile foundation) and two different heights of scaled prototype steel building frame have been considered. The analysis was performed in Heavy Structural Engineering Lab at N.I.T Patna, and soil has been excavated from the campus. To consider the ovalling effect of tunnel, shake table was vibrated perpendicular to the axis of tunnel by taking El Centro N-S as input motion. After the analysis it was found that ovalling effect of circular tunnel mostly affects the displacement of building when the tunnel was situated just below the centre axis of building. Same result was found for all types of foundation. Influence of ovalling effect of circular tunnel diminished as the distance between the building frame and tunnel increases. Response of building, constructed over isolated foundation was found to be the mostly effected as compared to the building constructed over other two types of foundation, while building constructed over pile foundation was the least affected. Shake table results show that high-rise prototype scaled steel building is much affected as compared to low-rise prototype scaled steel building frame. The results help in acknowledging the fact that foundation type should be considered for investigating the effect of tunnels during seismic excitation. [ABSTRACT FROM AUTHOR]

Inclinometer probes are devices that can be used to measure deformations within earthwork slopes. This paper demonstrates a novel application of Bayesian techniques to real‐world inclinometer data, providing both anomaly detection and forecasting. Specifically, this paper details an analysis of data collected from across the entire UK rail network. Inclinometers are a standard tool of geotechnical site monitoring. Data from these instruments is often used in risk analysis and decision‐making. However, discerning anomalous data points and forecasting future behaviour from inclinometer data requires significant 'engineering judgement' (subjective appraisal). This is because the observational data is derived from complex physical phenomena and contains complex spatio‐temporal correlations. Additionally, the practical demands of data collected from remote sites over several years tends to introduce systematic errors. These issues make the interpretation of inclinometer data challenging. Practitioners have effectively two goals when processing monitoring data. The first is to identify any anomalous or dangerous movements, and the second is to predict potential future adverse scenarios by forecasting. In this paper we apply Uncertainty Quantification (UQ) techniques by implementing a Bayesian approach to anomaly detection and forecasting for inclinometer data. Subsequently, both costs and risks may be minimised by quantifying and evaluating the appropriate uncertainties. This framework may then act as an enabler for enhanced decision making and risk analysis. We show that inclinometer data can be described by a latent autocorrelated Markov process derived from measurements. This can be used as the transition model of a non‐linear Bayesian filter. This allows for the prediction of system states. This learnt latent model also allows for the detection of anomalies: observations that are far from their expected value may be considered to have 'high surprisal', that is they have a high information content relative to the model encoding represented by the learnt latent model. We successfully apply the forecasting and anomaly detection techniques to a large real‐world data set in a computationally efficient manner. Although this paper studies inclinometers in particular, the techniques are broadly applicable to all areas of engineering UQ and Structural Health Monitoring (SHM). [ABSTRACT FROM AUTHOR]

This paper sheds light on civil facilities that are home to the underrepresented and overlooked population with mental illnesses. More specifically, this paper examines the primary architectural engineering features of psychiatric hospitals from the lens of fire hazards. Psychiatric hospitals rose in popularity in the nineteenth century for individuals deemed unfit to live with the sane population. While they began with good intentions, these hospitals came to represent practices and poor living conditions for mentally ill patients. These conditions, when combined with a wide variety of mental illnesses, resulted in increased risks. One of the most significant risks in psychiatric hospitals was fire—with nearly all psychiatric hospitals examined herein experiencing at least one structural fire despite premier fire control inclusions. A brief history of psychiatric hospitals is presented first, followed by a discussion on various aspects of structural fire design. Then, an analysis of structural fires in psychiatric hospitals throughout the world is performed, and three general and common fire causes and mitigation strategies are presented. Perhaps current and future professionals can better mitigate fire risk in healthcare design by understanding where past architects and designers lacked in designs for vulnerable populations. This paper examines an often overlooked portion of the world's mental health history by shedding light on one of the most significant risks associated with nineteenth- and twentieth-century psychiatric hospitals: fire. A brief introduction to historic mental health facilities and their populations is presented first, followed by a discussion on fire control methods of the past. Then, seven prominent facilities, or asylums, with a history of fire are analyzed for cause and mitigation strategies. As a result, three prominent contributions are discussed and include architectural and structural design, fire mitigation methods, and population characteristics. The goal of this analysis is to increase awareness of the many and broad vulnerabilities of populations (past and present) such as the mentally ill when placed in care facilities. Perhaps current and future professionals can better mitigate fire risk in healthcare design by understanding where past architects and designers lacked in designs for such people. [ABSTRACT FROM AUTHOR]

Purpose: In structural health monitoring, localization of multiple slight damage without baseline data is significant and difficult. The purpose of this paper is to discuss these issues. Design/methodology/approach: Damage in the structure causes singularities of displacement modes, which in turn reveals damage. Methods based on the displacement modes may fail to accurately locate the slight damage because the slight damage in engineering structure results in a relatively small variation of the displacement modes. In comparison with the displacement modes, the strain modes are more sensitive to the slight damage because the strain is the derivative of the displacement. As a result, the slight variation in displacement data will be magnified by the derivative, leading to a significant variation of the strain modes. A novel method based on strain modes is proposed for the purpose of accurately locating the multiple slight damage. Findings: In the two bay beam and steel fixed-fixed beams, the numerical simulations and the experimental cases, respectively, illustrate that the proposed method can achieve more accurate localization in comparison with the one based on the displacement modes. Originality/value: The paper offers a practical approach for more accurate localization of multiple slight damage without baseline data. And the robustness to measurement noise of the proposed method is evaluated for increasing levels of artificially added white Gaussian noise until its limit is reached, defining its range of practical applicability. [ABSTRACT FROM AUTHOR]

The inverse finite element method (iFEM) based on fiber grating sensors has been demonstrated as a shape sensing method for health monitoring of large and complex engineering structures. However, the existing optimization algorithms cause the local optima and low computational efficiency for high-dimensional strain sensor layout optimization problems of complex antenna truss models. This paper proposes the improved adaptive large-scale cooperative coevolution (IALSCC) algorithm to obtain the strain sensors deployment on iFEM, and the method includes the initialization strategy, adaptive region partitioning strategy, and gbest selection and particle updating strategies, enhancing the reconstruction accuracy of iFEM for antenna truss structure and algorithm efficiency. The strain sensors optimization deployment on the antenna truss model for different postures is achieved, and the numerical results show that the optimization algorithm IALSCC proposed in this paper can well handle the high-dimensional sensor layout optimization problem. [ABSTRACT FROM AUTHOR]

Virtual Reality (VR) provides an immersive and engaging experience that facilitates the teaching and learning of abstract concepts. This paper describes the design and implementation of the VR 360° (VR360) component of the Virtual and Augmented Reality for Structures (VARS) mobile application. This study used VARS to teach basic structural systems to 109 project and facilities management undergraduates. Based on a questionnaire survey, most students agreed that VARS VR360 helped them achieve learning outcomes. Furthermore, the study found that physics background and cybersickness did not influence the perceived effectiveness of the application, but authentic context and immersiveness are important design elements. The contributions of this paper are threefold: (1) the development of a VR360 mobile application for teaching basic structural systems concepts to non-engineering students; (2) the demonstration of how VR360 can be an effective medium for improving the teaching of structural systems to non-engineering students; (3) the identification of critical design elements and factors that influence the perceived effectiveness of VR360 educational technology. [ABSTRACT FROM AUTHOR]

Nerve repair and regeneration are still challenging issues in the world, mainly due to the complex anatomic structure and limited regeneration ability of natural nerves. Tissue engineering provides a structure and function similar to nerve tissue through scaffold materials, seed cells, and active factors, which is a promising method to treat nerve injury. Gelatin methacrylate (GelMA) hydrogel is a kind of gelatin modified by methacrylamide, which possesses adjustable mechanical properties, convenient processability, and excellent biocompatibility, has been widely used in nerve tissue engineering. In this paper, the research progress of GelMA-based hydrogel in nerve repair and regeneration in recent five years is reviewed, with emphasis on the advanced manufacturing technologies of three-dimensional (3D) GelMA scaffold and the application systems that can effectively promote nerve repair and regeneration. We also evaluated the challenges and prospects of GelMA-based hydrogels in the field of nerve repair and regeneration, which is of guiding significance to the research of nerve tissue engineering. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents analysis of a 3-dimensional engineered structural panel (3DESP) having a tri-axial core structure made from phenolic impregnated laminated-paper composites with and without high-strength composite carbon-fiber fabric laminated to the outside of both faces. Both I-beam equations and finite element method were used to analyze four-point bending of the panels. Comparisons were made with experimental panels. In this study, four experimental panels were fabricated and analyzed to determine the influence of the carbon-fiber on bending performance. The materials properties for finite element analyses (FEA) and I-beam equations were obtained from either the manufacturer or in-house material tensile tests. The results of the FEA and I-beam equations were used to compare with the experimental 3DESP four-point bending tests. The maximum load, face stresses, shear stresses, and apparent modulus of elasticity were determined. For the I-beam equations, failure was based on maximum stress values. For FEA, the Tsai-Wu strength failure criterion was used to determine structural materials failure. The I-beam equations underestimated the performance of the experimental panels. The FEA-estimated load values were generally higher than the experimental panels exhibiting slightly higher panel properties and load capacity. The addition of carbon-fiber fabric to the face of the panels influenced the failure mechanism from face buckling to panel shear at the face–rib interface. FEA provided the best comparison with the experimental bending results for 3DESP. [Copyright &y& Elsevier]

In order to quantitatively calculate the critical depth and critical load of mines affected by rock burst, and to achieve effective prevention and control of rock burst in coal mines, this paper proposes a mechanical model for predicting the occurrence of rock burst in coal mine roadways based on catastrophe theory. Additionally, a theoretical calculation formula for initiating rock burst is derived. The first step was to establish a mechanical analysis model, which directly correlated with the in-situ stress, physical and mechanical characteristics of the coal-rock mass, and engineering structural parameters. Following this, a mechanical instability criterion was derived for the key load-bearing circle within the surrounding rock of the roadway. In the final step, the critical depth and load for rock burst initiation were verified for 25 distinct coal mines in China that were prone to rock burst hazards. The research results demonstrate that the discrepancy between the theoretically calculated critical depth and the actual measured statistical values was less than 35%. In addition, the difference between the theoretically determined critical depth and the value calculated by Pan Yishan was less than 32%. Notably, the ratio of the theoretically calculated critical load to the uniaxial compressive strength of the coal-rock mass ranged from 0.38 to 1.93. This aligns with empirical data on rock burst occurrences, as set out in the engineering classification standards for rock masses. These research outcomes substantiated the practical utility of the proposed theory, thereby laying a robust theoretical groundwork for the quantitative control of rock burst. [ABSTRACT FROM AUTHOR]

Space grid structures are widely used in the field of structural engineering due to their good mechanical properties and simple construction procedures. This paper reviews the development of space grid structures and mainly introduces the development of space grid structures in China in recent years. Some typical applications of space grid structures are introduced and the technical developments are summarized. It shows that China not only has a large number of engineering applications of space grid structures, but also a rapid development of related technologies. Finally, some prospects for space grid structures are discussed. [ABSTRACT FROM AUTHOR]

In the field of aerospace and advanced equipment manufacturing, accurate response analysis has been paid more attention, requiring a more comprehensive study of the variation of mechanical parameters with the service environment. The damping variation characteristics of 304 aluminum alloy, Sa564 high-strength alloy, GW63K magnesium alloy, and Q235 steel were investigated in this paper, which plays a significant role in the dynamic responses of structures. Variable damping ratios were revealed by the damping tests based on a dynamic mechanical analysis (DMA). The numerical method of temperature/frequency-dependent damping parameters in stochastic dynamics was focused on. With a large variation in the damping ratio, a numerical constitutive relation for temperature-dependent damping was proposed, and an efficient stochastic dynamics method was derived to analyze the responses of structures based on the pseudo excitation method (PEM) and variable damping theory. The computational accuracy and validity of the proposed method are confirmed during the vibration tests and numerical analysis. Based on the comparison results of the two damping models and the experiments on GW63K alloy, we proved that the proposed method is more accurate to the real response of the actual engineering structure. The differences in dynamic responses between the constant damping and experiments are significant, and more attention should be paid to the numerical method of stochastic dynamic response of variable damping materials in the aviation and aerospace fields and high-temperature environments. [ABSTRACT FROM AUTHOR]

External prestressing is widely employed in structural strengthening engineering due to its numerous advantages. However, external prestressed steel bars are prone to corrosion when exposed to the service environment. This paper is dedicated to examining the use of fiber-reinforced polymer (FRP) bars as external prestressing materials to strengthen one-way concrete slabs. Five one-way concrete slabs were strengthened with externally prestressed FRP bars with different prestress levels and different amounts of FRP bars, while one non-strengthened slab was used for comparison. The effects of strengthening on the flexural behavior, specifically the cracking load, ultimate load, stiffness and failure mode, were analyzed systematically. Moreover, the ductility and cost–benefit optimizing properties of the reinforcing design were discussed. The results show that external prestressed FRP bars significantly improve the cracking load, ultimate load and stiffness of one-way concrete slabs. The absence of a bond between the concrete and FRP bars overcomes the brittleness of the FRP bars, while the strengthened slabs exhibit satisfactory ductility and a higher post-yield stiffness and bearing capacity. Additionally, the cost/benefit ratio is optimized by increasing the prestress level, while a higher number of prestressed FRP bars is beneficial to ductility. Finally, a method for calculating the stress in prestressed FRP bars at ultimate loads was proposed. Irrespective of the prestressing material, this method is applicable to both strengthened beams and one-way slabs. [ABSTRACT FROM AUTHOR]

Lug is one of the most important lap joints in many engineering structures, especially airframes. Through‐thickness and part‐through cracks emanating from pin‐loaded lug hole are frequently encountered due to stress concentration. Stress intensity factors for various crack geometries are the prerequisite for damage tolerance design of attachment lug. In this paper, analytical 2D weight functions for through‐thickness crack in lug are derived considering the contact condition between the pin and lug. With the derived 2D weight function, a highly efficient 3D slice synthesis weight function method (SSWFM) is then developed to determine 3D SIFs of hole‐edge corner/surface crack in straight and tapered lugs under various pin loadings. The resulting 3D SIFs are verified by comparisons with the numerical FEM/Franc3D solutions and literature data. The SSWFM is about 1800 times faster than the numerical FEM/Franc3D and therefore will significantly enhance damage tolerance analysis capability for attachment lugs. Highlights: Accurate and wide‐range weight functions of pin‐loaded cracked lug are derived considering the contact constraint.A 3D weight function method for corner and surface cracks of lug is established.It is accurate and much faster than FEM for SIF calculation. [ABSTRACT FROM AUTHOR]

Concrete-filled steel tubular (CFST) columns have extensive applications in structural engineering due to their exceptional load-bearing capability and ductility. However, existing design code standards often yield different design capacities for the same column properties, introducing uncertainty for engineering designers. Moreover, conventional regression analysis fails to accurately predict the intricate relationship between column properties and compressive strength. To address these issues, this study proposes the use of two machine learning (ML) models—Gaussian process regression (GPR) and symbolic regression (SR). These models accept a variety of input variables, encompassing geometric and material properties of stub CFST columns, to estimate their strength. An experimental database of 1316 specimens was compiled from various research papers, including circular, rectangular, and double-skin stub CFST columns. In addition, a dimensionless output variable, referred to as the strength index, is introduced to enhance model performance. To validate the efficiency of the introduced models, predictions from these models are compared with those from two established standard codes and various ML algorithms, including support vector regression optimized with particle swarm optimization (PSVR), artificial neural networks, XGBoost (XGB), CatBoost (CATB), Random Forest, and LightGBM models. Through performance metrics, the CATB, GPR, PSVR and XGB models emerge as the most accurate and reliable models from the evaluation results. In addition, simple and practical design equations for the different types of CFST columns have been proposed based on the SR model. The developed ML models and proposed equations can predict the compressive strength of stub CFST columns with reliable and accurate results, making them valuable tools for structural engineering. Furthermore, the Shapley additive interpretation (SHAP) technique is employed for feature analysis. The results of the feature analysis reveal that section slenderness ratio and concrete strength parameters negatively impact the compressive strength index. [ABSTRACT FROM AUTHOR]

• A high-efficient model for vehicle-track-soil dynamic interaction based on hybrid solution method. • Cyclic calculation boundary and multi-time-step strategies are integrated into the hybrid model. • The proposed hybrid model can evaluate the vehicle-track-soil performance efficiently without losing accuracy. To meet the demand for dynamic analysis of railway engineering structures accurately, the numerical model considering the coupled vibrations of the vehicle, track and substructure becomes a research tendency. However, it generates low-efficiency risk due to high degrees of freedom of the model. In this paper, a hybrid integration method based on the implicit scheme and Green's function is introduced and combined with the cyclic calculation method and the multi-time-step solution method to optimize the dynamic procedure for high-efficient solution of vehicle-track-soil (VTS) dynamic interaction. The VTS system is divided into two sub-models: vehicle-rail sub-model and the track slab-soil sub-model. The compatibility between two sub-models is maintained by the equilibrium mechanism of the fasteners' interaction forces. Through detailed validation, discussion and numerical studies, the feasibility and efficiency of the proposed model combing the hybrid integration method and two optimized dynamic solution strategies are fully demonstrated in the dynamic assessment of VTS dynamic interaction. [ABSTRACT FROM AUTHOR]