Structures最新文献

{"title":"Compressive behavior of recycled aggregate concrete-filled square steel tubular columns with FRP–confined concrete core","authors":"Yue-Ling Long ,&nbsp;Bo-Song Li ,&nbsp;Yao-Ming Liu ,&nbsp;Guang-Ming Chen ,&nbsp;Ming-Xiang Xiong","doi":"10.1016/j.istruc.2025.108915","DOIUrl":"10.1016/j.istruc.2025.108915","url":null,"abstract":"<div><div>To expand recycled aggregate concrete (RAC) application to structures, this study experimentally investigated the compressive behaviour of a composite column, called RAC-filled square steel tubular columns with FRP-confined concrete core (SCFC). The study aimed to compare the behaviour of this type of column with those using natural aggregate concrete (NAC) and explore the different confinement mechanisms between SCFC and single-steel tube confined concrete (concrete-filled steel tube (CFST)). The experimental results demonstrated the influence of RAC on the axial load–strain response. However, this effect could be eliminated by increasing the confinement. The confining effects triggered by the square steel tube and FRP tube on the concrete did not reach the maximum simultaneously. Therefore, the peak load was slightly affected. However, the ductility improved significantly, and good deformation compatibility was achieved. Accordingly, an analysis-oriented stress–strain model capable of capturing the load–strain response of RAC-filled square SCFC columns under axial compression was developed.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 108915"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144099001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-driven structural health monitoring: STFT-based feature extraction for damage detection","authors":"Rakesh Katam ,&nbsp;Venkata Dilip Kumar Pasupuleti ,&nbsp;Prafulla Kalapatapu","doi":"10.1016/j.istruc.2025.109244","DOIUrl":"10.1016/j.istruc.2025.109244","url":null,"abstract":"<div><div>Structural health monitoring (SHM) is essential for ensuring the safety and durability of engineering structures by enabling early identification of damage. This research presents a novel approach that integrates experimental testing, signal processing, and machine learning to enhance damage detection in cantilever beams, mainly when working with limited datasets. Vibration-based time-series data (VBTSD) are gathered from damaged and undamaged beams, utilizing fast fourier transform (FFT) and short-time fourier transform (STFT) for frequency-domain analysis. While FFT delivers a comprehensive spectral overview, STFT provides a focused time-frequency analysis, effectively capturing transient structural changes that are critical for early damage detection. To manage the high-dimensional STFT feature space, an autoencoder is utilized to extract compressed yet informative representations while preserving essential frequency-magnitude variations. The resulting encoded features are then used to train a support vector machine (SVM) classifier, achieving an impressive 98 % accuracy in predicting the presence of structural damage. The proposed framework is designed to function effectively even with limited data availability, ensuring robustness in real-world SHM applications where data collection is often restricted. The high-resolution frequency selectivity offered by STFT surpasses traditional methods such as wavelet transforms and standalone FFT, making it exceptionally suitable for real-time damage detection. This research highlights the combination of vibration-based feature extraction and machine learning, resulting in a scalable, data-efficient, and computationally feasible approach for SHM. The results aid in the progression of automated damage classification, presenting a practical and dependable resource to improve structural resilience and safety within civil engineering applications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109244"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144099002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simplified design methods of large-capacity moment end-plate connections","authors":"Xiuli Liu ,&nbsp;Xiaolin Sha ,&nbsp;Chao Guo ,&nbsp;Yan Wang ,&nbsp;Zhenshuo Zhang","doi":"10.1016/j.istruc.2025.109095","DOIUrl":"10.1016/j.istruc.2025.109095","url":null,"abstract":"<div><div>As the moment resistance demand for beam-to-column connections increases in steel frames involving large spans or heavy loads, ordinary extended end-plate connections may not satisfy the resistance requirement, which is limited by the axial tension capacity of the bolts. Consequently, additional bolts are necessary in moment end-plate connections to meet this requirement. In this case, large-capacity connections with more than 4 bolts in tension region are proposed. The mechanical properties of large-capacity end-plate connections are more complex than those of ordinary end-plate connections. Therefore, although the research of ordinary end-plate connections is extensive, it could not be directly applied to the design of large-capacity connections. To address this issue and provide a unified approach with ordinary end-plate connections, a simplified prediction of end-plate thickness and prying force is suggested in this paper. By considering both the yield-line theory and T-stub model together, a simplified design procedure was proposed for large-capacity end-plate connections. And an appropriate regression value for the effective length based on specific equivalent T-stub models is suggested in this paper. Through comparative analysis, it is found that the method proposed in this paper has a better agreement with the experimental and finite element results than the design results of the LRFD and ASD codes. In addition, considering the influence of some detailed configuration such as flush end plate at lower end, extension stiffeners, center bolts at x axis of beam etc., the methods proposed in this study provided sufficiently accurate results and wider applicability. Furthermore, the prediction of end-plate thickness and prying force of the wide ＆ long end plate connection is also proposed in this paper, which has not been mentioned in all the current specifications. In summary, the predictions of end-plate thickness and prying force proposed in this paper is not only simple and easy to calculate, but also has good accuracy and wider applicability. It can provide a key step for the design of large-capacity end-plate connections. It can also provide basic research data for the popularization and application of large-capacity end-plate connections.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109095"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144099003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithm for automated generating pitting surfaces on steel structures in offshore and atmosphere environments","authors":"Xu Jiang,&nbsp;Hao Qi,&nbsp;Xuhong Qiang,&nbsp;Xuanyi Lei","doi":"10.1016/j.istruc.2025.109182","DOIUrl":"10.1016/j.istruc.2025.109182","url":null,"abstract":"<div><div>The occurrence of pitting damage in steel structures has been identified as a significant threat to their mechanical properties and overall safety in atmosphere and offshore environments. The utilization of generative algorithms to generate pitting surfaces on steel structures in large quantities has the potential to facilitate further research on pitting in finite element analysis and deep learning. This study employed the fractal interpolation algorithm and the W-M surface, a fractal characteristic surface, to simulate the initial roughness of the steel structure. The ideal pitting surface, generated based on a statistical distribution model, was then subjected to geometric complexity, resulting in the fractal pitting surface for steel structures with pronounced fractal characteristics. A real pitted component was scanned using a 3D laser scanner to obtain the real pitting surface. By comparing the statistical and geometric characteristics of the real pitting surface with the generated pitting surface, it was proved that the pitting surface generated by the algorithm proposed in this study could well match the real pitting surface in terms of statistical and geometric characteristics, and it was confirmed that the algorithm could be used to automatically generate pitting surfaces with highly complex geometry and obvious pitting characteristics. The findings of this study can provide a basis for further applications of Synthetic data in the study of corrosion in steel structures in different environments.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109182"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crack detection and 3D visualization of crack distribution for UAV-based bridge inspection using efficient approaches","authors":"Yahui Qi ,&nbsp;Pengzhen Lin ,&nbsp;Guojun Yang ,&nbsp;Tao Liang","doi":"10.1016/j.istruc.2025.109075","DOIUrl":"10.1016/j.istruc.2025.109075","url":null,"abstract":"<div><div>In order to improve the detection accuracy and efficiency of bridge crack detection models, while addressing the challenge of crack localization, this paper proposes an efficient Unmanned Aerial Vehicle (UAV)-based concrete bridge crack detection framework. The framework includes depth-based Regions of Interest (ROI) extraction, an improved YOLOv11 crack detection model, the SeaFormer lightweight crack segmentation model, an image quality assessment model, a pseudo-crack removal algorithm, the conversion of pixel values to actual values, and an efficient crack detection scheme. Comparative testing with mainstream models demonstrates the advantages of the proposed models in detection accuracy, localization accuracy, and lightweight design. Additionally, a multi-view 3D reconstruction scheme is proposed, offering lower memory and time requirements while improving performance. Combined with the aforementioned crack detection models, it achieves 3D reconstruction of bridge structures and visualization of the 3D distribution of cracks. In tests involving images of cracks from the piers of Zhongshan Bridge in Lanzhou, the crack identification accuracy reaches 93.2%, with an F1 score of 87.7% and a recall rate of 82.7%. The crack segmentation accuracy is 93.66%, and the Intersection over Union (IoU) is 90.17%. The results show that the proposed bridge crack detection framework delivers high lightweight performance and detection efficiency while maintaining high accuracy, making it more suitable for deployment on mobile devices such as UAVs for crack detection in bridges, towers, and other structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109075"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of material properties and reinforcement on the compressive and shear strengths of concrete masonry: An experimental study","authors":"AbdelRahman AbdAllah ,&nbsp;Belal AbdelRahman ,&nbsp;Khaled Galal","doi":"10.1016/j.istruc.2025.108936","DOIUrl":"10.1016/j.istruc.2025.108936","url":null,"abstract":"<div><div>The shear strength of reinforced masonry (RM) walls is influenced by the properties of blocks, mortar, grout, and reinforcement. Despite extensive research on the impact of these elements on masonry compressive strength, there is, to the knowledge of the authors, a notable gap in studies examining their effects on shear strength. This study experimentally investigates the influence of mortar and grout strengths, as well as vertical and horizontal reinforcement, on the compressive and shear stress-strain responses of concrete masonry prisms and assemblages. A total of 40 masonry prisms and 34 masonry assemblages were tested under concentric axial compression and diagonal tension loads, respectively. The behavior of prisms and assemblages was analyzed in terms of compressive and shear strengths, strain at peak stress, modulus of elasticity and rigidity, ultimate ductility index, and modulus of toughness. Additionally, the experimental results were compared with available equations in the literature and North American standards (i.e., CSA S304–14&amp;24 and TMS 402/602–22) for predicting the compressive and shear masonry strengths. The findings reveal that increasing the mortar or grout strengths significantly enhance masonry shear strength but has a less pronounced effect on compressive strength. The presence of vertical or horizontal reinforcement alone or in combination contributes positively to masonry shear strength. For compression prisms, both superposition of masonry shell and grout core strengths and most existing literature equations tend to overestimate masonry compressive strength. The available literature equations for predicting masonry shear strength showed good agreement with the experimental results of this study. CSA S304–14&amp;24 equations overestimate masonry compressive strength but underestimate shear strength, whereas TMS 402/602–22 underestimates both. This study highlights the need for better prediction methods for both compressive and shear strengths of concrete masonry in North American design standards.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 108936"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved Stockwell transform on the estimation of the evolutionary spectrum for nonstationary typhoons","authors":"Bo Xie,&nbsp;Xiaoqun Luo,&nbsp;Qilin Zhang","doi":"10.1016/j.istruc.2025.109199","DOIUrl":"10.1016/j.istruc.2025.109199","url":null,"abstract":"<div><div>Accurate evolutionary power spectral density (EPSD) estimation for monitored typhoon winds is of significance in studying time-varying properties. Current estimation approaches, such as Priestley-based and wavelet-based approaches, all have certain limitations in their widespread practical applications. In this study, an improved Stockwell-transformed-based (IST) approach was proposed to enhance its estimation accuracy and applicability. A novel window function, called the <em>k-th</em> power half cosine function, was adopted to represent the traditional Gaussian window in the traditional ST, which could adaptively control the window size by selecting different parameters of <em>k</em>. To reduce the estimation error, the even <em>k</em> was recommended, and the series expansion was also employed. Two numerical cases that represented uniformly modulated winds and non-uniformly modulated winds were simulated to investigate the estimation performance of the proposed IST. Moreover, the Priestley-based and wavelet-based approaches were also applied to compare the estimated results with IST. The comparison demonstrated greater accuracy of the IST, which indicated that IST outperformed the Priestley-based and wavelet-based approaches. Finally, the IST was successfully carried out to estimate time-varying spectra for monitored typhoon Jongdary (2018) atop the Shanghai Tower (ST). The investigation for monitored typhoon spectra revealed that typhoon winds displayed remarkably time-varying spectra. A time-varying Von Karman spectrum model was utilized to characterize the estimated EPSDs by the IST, and its characterization performance was evaluated in detail. Therefore, this study could provide a valuable route to study nonstationary typhoon spectra.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109199"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probabilistic analysis of cracking in concrete floor slabs under seismic loading and interactions with Power Actuated Fasteners (PAF)","authors":"Alhussain Yousef,&nbsp;Panagiotis Spyridis","doi":"10.1016/j.istruc.2025.109230","DOIUrl":"10.1016/j.istruc.2025.109230","url":null,"abstract":"<div><div>Power Actuated Fasteners (PAFs) are commonly used in construction for non-structural applications like fixing electrical components or installing drywall partitions mounted on either side of concrete floor slabs in seismic and non-seismic regions today. They are known for their efficiency and cost-effective installation process. However, the behavior of PAFs under seismic conditions is not fully understood, and there is a lack of seismic qualification criteria for such systems. This paper presents a probabilistic analysis of cracking in concrete slabs assuming seismic design situations and interactions with PAF. For this investigation, a model was programmed to predict the expected crack pattern due to various limit states. The model integrates a large database of standard materials and allows for various geometric and material configurations of the concrete slab, reinforcement steel, and boundary conditions. The calculation of the cracks is based on widely acknowledged equations, in line with Eurocode 2. These are then integrated into stochastic models with randomly generated parameters as input for iterations assuming common concrete floor slab configurations. The assumed boundary conditions under various load conditions, are linked to earthquake situations and they provide insights into the interaction between PAF fixtures and cracks in concrete slabs. The investigation was concluded by conducting trials against two specific limit states: Diaphragm shear strength and steel yielding in shear. The results of the investigation revealed a range of crack widths that occurred as a result of applying these limit states, which may be considered for future seismic pre-qualification testing of PAF.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109230"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical properties of extrusion-based 3D-printed concrete considering the thickness of the printed layer and printing time interval","authors":"Boyang Tang ,&nbsp;Jiachuan Yan ,&nbsp;Xiaoyu Han ,&nbsp;Yini Lin ,&nbsp;Feng Fan","doi":"10.1016/j.istruc.2025.109225","DOIUrl":"10.1016/j.istruc.2025.109225","url":null,"abstract":"<div><div>This paper investigated the performance of 3D printed concrete with a focus on the bonding layer, considering the thickness of the printed layers. Through experimental testing and numerical simulation, the mechanical properties and failure mechanisms of the bonding layer were thoroughly analyzed. The results revealed that compressive strength diminishes with thinner layers and longer printing intervals, while anisotropic mechanical properties become increasingly pronounced with reduced layer thickness. The static performance of 3D printed concrete arches was also studied, showing that increased layer thickness enhances the ultimate load bearing capacity. Cohesive elements were used to simulate compressive strength across varying layer thicknesses and printing time intervals. Prediction formulae for compressive strength were developed and validated through experimental data. The study further simulated the static performance of arches using both cohesive elements and anisotropic material properties, confirming the accuracy of the strength prediction formulae and the effectiveness of the simulation methods.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109225"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Punching shear capacity of rubberized high strength concrete slabs containing waste glass powder as cement substitute","authors":"Ahmed D. Almutairi ,&nbsp;Mahmoud Elsayed ,&nbsp;Mohamed M. Abdelaziz ,&nbsp;Hany A. Dahish","doi":"10.1016/j.istruc.2025.109222","DOIUrl":"10.1016/j.istruc.2025.109222","url":null,"abstract":"<div><div>This paper investigates the combined effect of crumb rubber (CR) and waste glass powder (WGP), which are partially substituted for fine aggregates (FA) and cement in concrete, respectively, on the punching shear behavior of high-strength concrete (HSC) slabs. Twelve separate concrete mixes were produced, each of which had a different ratio of CR and WGP. With 10 % incremental steps for each, four WGP levels varied from 0 % to 30 % as cement substitution and three CR levels varied from 0 % to 20 % as FA substitutes were considered. A total of twelve 1000 × 1000 × 100 mm simply supported reinforced HSC slabs were prepared and tested. The experimental findings revealed that the inclusion of 10 % WGP as a cement substitution resulted in a remarkable improvement in the punching shear capacity (<em>V</em>_<em>u</em>). On the contrary, the inclusion of CR caused a negative impact on the <em>V</em>_<em>u</em> of HSC slabs. From an engineering and environmental perspective, the mix containing a combination of 10 % WGP and 10 % CR proved to be the most suitable, as it has a slight impact on the <em>V</em>_<em>u</em> of HSC slabs. Five different approaches (ACI 318–2019, CSA A23.3, BS8110, Euro Code 2, and ECP 203) were used to predict the Vu, and the predictions were compared with the experimental findings. Moreover, the Applied Element Method was used to perform a numerical simulation of the slabs to validate the experimental findings and gain additional insights into the punching shear behaviour. The numerical model was calibrated against experimental data, achieving a mean error of approximately 1 % in ultimate shear force and ultimate deflection. The satisfactory agreement between the numerical and experimental results confirms the reliability and validity of the slabs' numerical modeling.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109222"},"PeriodicalIF":3.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}