Structures最新文献

{"title":"Bending failure mechanisms and kinematics of micropile threaded connections","authors":"Sebastian Montoya-Vargas ,&nbsp;Aaron Gallant ,&nbsp;William G. Davids ,&nbsp;Keith Berube","doi":"10.1016/j.istruc.2025.109223","DOIUrl":"10.1016/j.istruc.2025.109223","url":null,"abstract":"<div><div>Micropiles are used in a broad array of applications that impose substantial bending loads, including slope stabilization, foundations for integral abutment bridges, offshore structures and wind turbine towers, among others. For these applications, the flexural capacity of micropile threaded joints must be quantified. This study details a comprehensive testing program designed to assess the relative influence of thread details and casing geometry on the failure mode (jump-out versus rupture), and flexural capacity of micropile threaded joints. Four-point bending tests on grout-filled steel micropile specimens were performed to assess the flexural weakness and failure mechanisms at threaded joints. A total of 31 tests were performed on casings with nominal outer diameters of 178, 194, 244, and 346 mm and threaded joints of varying lengths and thread shapes. Displacements were measured with string potentiometers and detailed strain distributions around threaded connections were assessed via digital image correlation (DIC) techniques. The DIC measurements illustrated that the extent of plastic deformation and failure was strongly influenced by the development of hoop strains around the box-end of the connections. It was found that casing diameter, threaded length, thread shape and wall-taper of the casing govern the overall connection behavior and associated failure mode and flexural strength.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109223"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168268","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":"Evaluating viscous damping for seismic energy dissipation in downscaled concrete structures under consistent earthquake loadings","authors":"Weng Khuen Chong ,&nbsp;Jing Ying Wong ,&nbsp;Chun Chieh Yip ,&nbsp;Lloyd Ling ,&nbsp;Mugahed Amran","doi":"10.1016/j.istruc.2025.109313","DOIUrl":"10.1016/j.istruc.2025.109313","url":null,"abstract":"<div><div>Earthquakes pose significant risks to low-rise reinforced concrete (RC) buildings, particularly in developing countries, where such structures remain the most common building type. This research identified gaps in analysing consistent earthquake scenarios rather than relying solely on the resistance of structural elements to historical ground motion. It also addressed missing factors in similitude laws for downscaled experimental models. Current study constructed a 1:8 downscaled reinforced concrete structure (DRCS), modelled after an existing school building which accurately reflects its prototype. The research examined the seismic performance of the structure with and without three different viscous damper coefficients under 10 levels of consistent seismic loading. Acceleration-based similitude law was utilised to downscale building and the viscous dampers, followed by an assessment of seismic responses on a shaking table, simulating seismic loading reaching up to 3.15 g, equivalent to a 4,000-year return period in New York City. Findings indicate that damper 3 with medium damping coefficient (DC) excellent in tackling S-wave and strong vibration phases, while damper 2 was most effective during the P-wave phase under consistent seismic loadings test. Validation of the proposed downscaling factors demonstrated high accuracy, with only a 1 % discrepancy between the prototype shear values derived from the downscaling factors and those obtained from the full-scale model. This study contributes to experimental seismic research by promoting consistent seismic loading evaluations over historical earthquake data, providing a more refined method for assessing viscous damping mechanisms and enhancing seismic resilience in structural engineering.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109313"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168282","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":"A mesoscale simulation on electromechanical admittance-based internal microcrack damage identification of concrete structure using polynomials spectral element method","authors":"Zeliang Yang ,&nbsp;Demi Ai ,&nbsp;Hongping Zhu","doi":"10.1016/j.istruc.2025.109247","DOIUrl":"10.1016/j.istruc.2025.109247","url":null,"abstract":"<div><div>Numerical simulation plays a key role in understanding the identification mechanism of concrete internal microcrack damage due to its inaccessibility and invisibility when using the electromechanical admittance (EMA) of surface-bonded piezoceramic (PZT) transducers. However, refined three-dimensional (3D) concrete mesoscale model for microcrack detection requires small element sizes for accurate electro-mechanical resolution and consequently results in considerable element nodes and computational consumption. To overcome the low efficiency of such a model, this paper proposed an integrated meso-element equivalent method (MEEM) and polynomials spectral element method (PSEM) to simulate the internal microcrack identification of concrete structure using the 3D concrete mesoscale model bonded with a PZT patch. The mesoscale model with side length of 100 mm was first established to obtain the EMA signatures of the concrete structure containing 30 % randomly distributed aggregates, which was compared with that using traditional finite element method (FEM) and validated by experimental measurements. Under the same boundary conditions and parameter settings, modelling validation demonstrated much higher accuracy with tested signatures both for the spectrum shapes and resonance amplitudes/frequencies meanwhile saving 62.5 % of element nodes and accelerating computational time by 14.7 times as compared with FEM. Model application to microcrack identification using the integrated PSEM-MEEM demonstrated that internal crack of concrete with minimum width of 0.1 mm, length of 2.5 mm and maximum 40 mm distant from concrete surface could be effectively identified in different orientations. Numerical results of this study provide a promising way of internal microcrack identification at mesoscale level of concrete modelling with high resolution, accuracy and efficiency.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109247"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168271","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 performance of column-column joints in ultra-low energy modular wall prefabricated building system","authors":"Weichao Li ,&nbsp;Haodong Zhang ,&nbsp;Wen-Tao Qiao ,&nbsp;Wencheng Xiao ,&nbsp;Yajing Wang","doi":"10.1016/j.istruc.2025.109315","DOIUrl":"10.1016/j.istruc.2025.109315","url":null,"abstract":"<div><div>This paper proposes a column-to-column connection for cold-formed, thin-walled steel-concrete composite columns in ultra-low energy modular wall prefabricated building system. The study investigates the effects of two parameters—section type and concrete confinement—through low-cycle reversed loading tests conducted on four sets of full-scale column-to-column connection specimens. The experimental results revealed the following findings: For cases without unconfined concrete, the failure modes in I-shaped column (I-S) and L-shaped column (L-S) structures were caused by excessive deformation of the steel section at the column base. In contrast, for cases with concrete, the failure modes of the I-shaped column (I-C) and L-shaped column (L-C) specimens involved concrete spalling at the column base and internal buckling of the steel section. Notably, the I-C specimen showed no significant damage at the column-to-column joint when the column failed, while the L-C joint failure occurred after the column base failure. With the same concrete parameters, the I-shaped column exhibited better load-bearing capacity and ductility when compared to the L-shaped column. Based on the experiments, a refined finite element model was developed, and a parametric analysis was performed. The influence of axial compression ratio, concrete strength, steel thickness, and connection plate thickness on structural load-bearing capacity and ductility was examined. The recommended ranges for these parameters are as follows: the axial compression ratio should not exceed 0.3; the concrete strength should be at least C30; the cold-formed thin-walled steel thickness should not be less than 1.8 mm; and connection plate thickness should not be less than 10 mm.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109315"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170602","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":"Freeze-thaw resistance and chloride permeability of circular CKD-based alkali-activated concrete","authors":"Omid Bamshad ,&nbsp;Amir Mohammad Ramezanianpour ,&nbsp;Alireza Habibi","doi":"10.1016/j.istruc.2025.109308","DOIUrl":"10.1016/j.istruc.2025.109308","url":null,"abstract":"<div><div>Alkali-activated concrete (AAC) is a sustainable construction material developed with industrial by-products to eliminate the use of cement in concrete production. The aim of this study was to develop AAC using cement kiln dust (CKD) and recycled alkali-activated concrete aggregate (RGA), namely circular alkali-activated concrete (CAAC), and its properties were compared with AAC, Portland cement concrete (PCC), and circular ordinary concrete (COC). The compressive strength of the four mix scenarios was designed in the same range. Several experiments including freeze-thaw resistance and chloride ion permeability, as well as micro-structural analysis were performed through mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results revealed that CKD-based CAAC and AAC had comparable durability properties to PCC and COC under freeze-thaw condition. So, the sorptivity coefficient of 28-day AAC, CAAC, PCC, and COC specimens after 50 freeze-thaw cycles was 0.226 kg/sec^0.5.m², 0.245 kg/sec^0.5.m², 0.317 kg/sec^0.5.m², and 0.388 kg/sec^0.5.m², respectively. Furthermore, the results of rapid chloride permeability test (RCPT), rapid chloride migration test (RCMT), and bulk electrical conductivity (BEC) showed that CKD-based CAAC and AAC had lower chloride ion penetration than COC and PCC. So, the migration coefficient of 28-day AAC, CAAC, PCC, and COC specimens was 7.5 E-12 m²/s, 8.8 E-12 m²/s, 17.7 E-12 m²/s, and 20.7 E-12 m²/s, respectively. Finally, the pore structure of the specimens revealed that the total porosity of alkali-activated specimens was less than PCC and COC before and after freeze-thaw cycles. The total porosity of 90-day AAC, CAAC, PCC, and COC specimens after 50 freeze-thaw cycles was increased by 1.95 %, 2.56 %, 3.27 %, and 4.18 %, respectively. It could be stated that regarding the minor difference between compressive strength, durability, and microstructure of CKD-based CAAC and AAC, using CKD-based CAAC is preferred.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109308"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170718","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":"Optimization of semi-active tuned mass damper inerter for enhanced vibration control of jacket platforms using multi-objective optimization due to environmental load","authors":"Seyed Hossein Hosseini Lavassani,&nbsp;Rouzbeh Doroudi,&nbsp;Seyyed Ali Mousavi Gavgani","doi":"10.1016/j.istruc.2025.109305","DOIUrl":"10.1016/j.istruc.2025.109305","url":null,"abstract":"<div><div>This study focuses on optimizing the vibration control of jacket platformsusing a semi-active tuned mass damper inerter (SATMDI) under the dynamic wave and wind loads. A Multi-Objective Observer-Teacher-Learner-Based Optimization (MOOTLBO) algorithm is employed to determine the optimal configuration of SATMDI dampers, addressing three main objectives: reducing the number of dampers, improving system performance (defined by five control indices), and minimizing the number of gears used. The proposed method is validated on the Ressalat platform, where numerical analysis reveals that the SATMDI system significantly reduces structural responses and dissipates energy effectively, even with fewer dampers compared to traditional systems. Results show that using a single optimized SATMDI damper with two gears offers the best performance in controlling vibrations while minimizing costs. The study also highlights the importance of optimal damper placement and gear configuration, demonstrating the system's ability to handle complex dynamic loads. This optimization approach not only enhances vibration mitigation but also reduces maintenance costs and extends the service life of offshore platforms.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109305"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168270","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":"Seismic response of neighboring irregular structures seated at different embedment depths considering soil-structure interaction","authors":"Gholamreza Keyvani Hafshejani,&nbsp;Pezhman Fazeli Dehkordi,&nbsp;Reza Ghaderi","doi":"10.1016/j.istruc.2025.109298","DOIUrl":"10.1016/j.istruc.2025.109298","url":null,"abstract":"<div><div>Typically, most structural modeling and analysis are performed assuming that structures are individually simulated. However, due to limited space, land value and population density, most buildings constructed in urban areas are located adjacent to one another. In seismic analyses, where soil-structure interaction (SSI) is of great importance, the adjacency of structures and foundation embedment depth could significantly influence the seismic response of structures. Previous studies have investigated SSI in adjacent structures positioned at a specific depth. However, the effect of SSI on the adjacency of structures positioned at different embedment depths has received less attention. Therefore, the present study aims to investigate the combined effect of different embedment depths and distances between the structures on the SSI response of irregular structures using Abaqus3D finite element analysis software. Displacement, stress and acceleration induced in the structures, as well as their interactions, are assessed by varying the distance between the structures from 2 to 10 m and altering embedment depths from 0 to 3 m, with the depth assumed to be a function of the structure’s width (B). The results indicate that altering the embedment depths of adjacent structures from 0 to 3 m reduces the effect of SSI from 31.2 % to 19.2 %, depending on the distance between the two structures, compared to the case where both structures are on the ground surface. The maximum SSI effect is achieved when the two structures are at the minimum distance from each other and both are located on the ground surface. The simultaneous effect of these two factors increases the influence of SSI by 84.4 %.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109298"},"PeriodicalIF":3.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170600","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":"Compressive and flexural properties of engineered geopolymer composites incorporating dune sands","authors":"Tianhe Zhang ,&nbsp;Qinghe Wang ,&nbsp;Qingxin Ren ,&nbsp;Tong Li ,&nbsp;Haoyue Sun ,&nbsp;Ji-nan Ding","doi":"10.1016/j.istruc.2025.109251","DOIUrl":"10.1016/j.istruc.2025.109251","url":null,"abstract":"<div><div>The integration of dune sand (DS) into engineered geopolymer composites (EGCs) has been shown to enhance their mechanical properties while simultaneously reducing dependence on ultrafine silica sand (SS), thereby contributing to cost-effective production. The study analyzes the effects of DS replacement ratios on EGC compressive and flexural properties across varying NaOH concentrations. Microstructural analysis, conducted using scanning electron microscopy (SEM), provides insights into the mechanisms underlying these improvements. Incorporating DS significantly boosts compressive and flexural strengths as well as toughness. The improvements stem from DS's pozzolanic activation at optimal NaOH levels, fostering secondary hydration and densifying the matrix. Maximum performance is recorded at 20 % NaOH, where DS addition enhances compressive strength by 18.18 %, flexural strength by 35.19 %, and midspan deflection to 105.27 mm. DS improves the fiber-matrix bond, enabling multiple cracking and strain-hardening. This enhanced fiber-matrix interaction contributes to superior energy absorption and improved ductility. To further characterize the mechanical behavior of EGCs, a refined stress-strain model is proposed, offering an accurate representation of both pre-peak and post-peak responses under uniaxial compression.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109251"},"PeriodicalIF":3.9,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168267","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":"Novel external dissipative device for rocking bridge columns: Resilient rotational friction elements","authors":"Hamdy Farhoud,&nbsp;Anthony Mackin,&nbsp;Islam M. Mantawy","doi":"10.1016/j.istruc.2025.109317","DOIUrl":"10.1016/j.istruc.2025.109317","url":null,"abstract":"<div><div>Rocking columns with internal reinforcement face challenges such as inelastic buckling, fracture due to low-cycle fatigue, and complex repair processes, which can compromise their resiliency after seismic events. This paper introduces the resilient rotational friction element (RRFE), an innovative external dissipative device designed to overcome inherent limitations in these rocking columns. By integrating controlled rotational friction mechanisms and self-centering prestressed strands, the RRFE enables damage-free seismic energy dissipation with superior structural resilience. Experimental evaluation under monotonic and cyclic loading validated the RRFE's robustness and energy dissipation capabilities. Monotonic tests demonstrated the influence of torque levels on frictional resistance with friction energy increasing from 0.10 to 1.11 kips·in, reflecting an 11-time increase when transitioning from snug-tightened to a 40 lb·ft torque level. A mechanistic model developed from monotonic tests provides predictive accuracy for friction energy design. Additionally, a theoretical framework was established to derive the rotational moment <em><strong>(M</strong></em>_{<em><strong>R</strong></em>}<em><strong>)</strong></em> based on Coulomb’s friction law and stress distribution principles. The developed equations, validated against experimental results, accurately capture the relationship between applied torque and axial post-peak behavior, providing a reliable tool for optimizing RRFE performance. Cyclic tests highlighted consistent energy dissipation and post-buckling performance across different specimens. Higher torque levels resulted in increased energy dissipation. The RRFE's adaptable design suits rocking systems such as concrete walls, steel columns, and mass timber walls, offering a cost-effective solution for new construction and retrofitting. This paper confirms the RRFE's potential as a transformative advancement in seismic-resistant design, addressing conventional system drawbacks and providing an efficient, repairable, and resilient solution for seismic-resistant structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109317"},"PeriodicalIF":3.9,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170717","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":"Axial compressive behavior of concrete-filled double-skin steel tubular columns with localized cracks","authors":"Tong Zhang ,&nbsp;Shiqi Huang ,&nbsp;Shan Gao","doi":"10.1016/j.istruc.2025.109302","DOIUrl":"10.1016/j.istruc.2025.109302","url":null,"abstract":"<div><div>Concrete-filled double-skin steel tubular (CFDST) columns are widely used in a wide range of applications such as high-rise buildings, long-span bridges, offshore platforms, and heavy-duty industrial structures. However, due to the exposed steel tube, the external steel tube of CFDST columns is prone to cracking during long-term service, which affects their normal and safe use. This paper presents the mechanical behavior of CFDST columns with localized cracks. The peak load, failure mode, and full-range load-strain curve were produced according to the FE (finite element) model which were all line up with the findings of the experimental study. The impact of localized cracks on the CFDST stub struts in terms of peak load, stiffness, and flexibility is evaluated. The results indicate that the crack length, crack width, and crack depth exert minimal influence on the ultimate load and stiffness of the specimen. The crack length, crack width, and crack depth significantly impact the specimen's ductility. The ductility of the specimen is rapidly reduced by 30.9 %, especially when the steel tubes are penetrated due to corrosion. The crack angle barely impacts the breaking strength of the specimen. As the crack angle increases, the stiffness gradually decreases and the ductility gradually increases. A predictive technique of an error of less than 6 % is shown for the axial compressive capacity of CDFST pile columns with localized cracks. Finally, the GA-BP neural network model demonstrates its improved accuracy and generalization ability by comparing the genetic algorithm to a standard BP neural network, exhibiting higher the coefficient of determination and lower prediction errors on training and test datasets.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"78 ","pages":"Article 109302"},"PeriodicalIF":3.9,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168269","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}