Structures最新文献

{"title":"Out-of-plane behavior and simplified modeling of reinforced masonry-infilled Chuan-dou timber frames","authors":"Ting Li ,&nbsp;Ming Xu ,&nbsp;Zhaoyan Cui ,&nbsp;Wei Chu","doi":"10.1016/j.istruc.2025.110238","DOIUrl":"10.1016/j.istruc.2025.110238","url":null,"abstract":"<div><div>The masonry-infilled Chuan-dou timber frame is a conventional structural system widely used in non-engineered residential buildings in China’s seismic regions. However, these structures are highly vulnerable to out-of-plane (OOP) failure for the absence of an effective connection between the infills and frames. This study investigates the OOP response of structures with infills-to-frames reinforcement through full-scale testing and finite element (FE) modeling. Two reinforcement strategies were considered: infills-beam and infills-column retrofitting. The results reveal that reinforcement alters both the failure modes and resistance mechanisms. Infills-beam retrofitting leads to unidirectional bending failure governed by vertical arching and reinforcement contribution. Infills-column retrofitting promotes bidirectional bending failure, with vertical and horizontal arching actions working together with reinforcement. FE analysis revealed sustained force increases in embedded ties, nails, and steel clamps after infill cracking, highlighting the critical role of reinforcement following arching failure. And simplified predictive models were proposed based on two- and three-side support boundary conditions. These models incorporate vertical and horizontal arching effects and quantify the relative contributions of reinforcement. The predicted OOP capacities agree well with test results, with a maximum error below 10 %.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110238"},"PeriodicalIF":4.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097259","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":"Flexural behavior of foamed concrete block masonry: A comparative study with AAC block masonry","authors":"Radwa Abdelhalim,&nbsp;Hesham Sokairge,&nbsp;Mahmoud Galal,&nbsp;Hany Elshafie","doi":"10.1016/j.istruc.2025.110262","DOIUrl":"10.1016/j.istruc.2025.110262","url":null,"abstract":"<div><div>Introducing lightweight concrete (LWC) blocks as an alternative to clay bricks in masonry walls is a promising application for lightweight concrete, which offers several structural and environmental advantages for green, sustainable buildings. The objective of this study is to evaluate the structural performance of masonry walls constructed using foamed concrete (FC) blocks compared to autoclaved aerated concrete (AAC) blocks by studying their compressive behavior, modulus of elasticity, and out-of-plane flexural performance. The variables considered in this study are the block type (AAC – FC) and the effect of plastering (without – with), in addition to the effect of span loading direction for flexural walls (parallel to bed joint “horizontally spanned” – perpendicular to bed joint “vertically spanned”). The test results showed that FC masonry walls exhibit lower out-of-plane flexural strength by about 40 % - 45 % than that of AAC masonry walls, which is attributed to the higher mechanical properties of available AAC blocks compared to those of available FC blocks. Both AAC and FC masonry vertically spanned walls showed 39 % - 50 % higher out-of-plane flexural strength compared to horizontally spanned walls. Plastering increased the out-of-plane flexural strength by 1.4 – 1.8 times for AAC masonry walls and by 2.4 – 4.1 times for FC masonry walls. Plastering mitigates the influence of both spanning direction and block strength on out-of-plane flexural strength for both AAC and FC masonry walls.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110262"},"PeriodicalIF":4.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097330","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":"An innovative two-stage damage detection method for space latticed structures","authors":"Shu-Hui Huang ,&nbsp;Die Hu ,&nbsp;Ze Yang ,&nbsp;Ming-Liang Zhu ,&nbsp;Tong Guo ,&nbsp;Zhi-Wei Shan ,&nbsp;Wei Chen ,&nbsp;Daniel Ting-Wee Looi ,&nbsp;R.K.L. Su","doi":"10.1016/j.istruc.2025.110225","DOIUrl":"10.1016/j.istruc.2025.110225","url":null,"abstract":"<div><div>Large span space latticed structures are widely used in public building structures. They inevitably suffer from damage attack during service process, which may weaken the mechanical properties of the structure. Therefore, it is necessary to conduct damage identification for these structures which can help evaluate their damage status. Because the structure form of space latticed structures differs from that of high-rise building and frame structures and number of members in large span space latticed structures are extremely numerous, there is short of an efficient and effective damage identification method that can be applicable to large span space latticed structures. In this case, an improved damage positioning method based on residual modal force is first developed, in which a weighting factor is assigned to the residual modal force of each modal order to impair the noise-induced effect on damage positioning. The effect of different modal expansion methods on this improved damage positioning method are investigated. It is found that kinetic condensation method is more preferable. Redundant undamaged members can thus be excluded in advance using this method, based on which an improved cross-model cross-mode (CMCM) method is developed for determining damage coefficients. Furthermore, an GA algorithm based optimal sensor placement method that can balance the improvement of the signal-to-noise ratio and the orthogonality condition for identified post-damage modal shapes is proposed, by which a more preferable damage identification effect is achieved. Finally, effect of critical parameters, i.e., number of post-damage and pre-damage modal orders, on the developed two-stage damage identification method is discussed.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110225"},"PeriodicalIF":4.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097331","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 and bond-slip behaviour of ultra-high performance concrete exposed to high temperature","authors":"Junjie Huang ,&nbsp;Jun Li ,&nbsp;Ruizhe Shao ,&nbsp;Zhenhuan Xu ,&nbsp;Pengtao Wu ,&nbsp;Chengqing Wu","doi":"10.1016/j.istruc.2025.110259","DOIUrl":"10.1016/j.istruc.2025.110259","url":null,"abstract":"<div><div>The residual mechanical behaviour, including the steel-concrete bond, was investigated in this research project for Ultra-high performance concrete (UHPC) with compressive strength of 101–134 MPa and maximum aggregate size below 0.04 mm. Specimens were heated to 200, 400, 600, 800 and 1000°C, reinforced with steel, polypropylene (PP), polyvinyl-alcohol (PVA) or hybrid fibres, for a total of six different mixes. Compressive, 4-point and pull-out tests were carried out to evaluate the compressive strength (on cylinders), the tensile strength (in bending) and bond strength, both at ordinary temperature (25°C) and after heating to high temperature and cooling down to room temperature. The test results show that (a) steel fibres guarantee a higher residual strength but fail to prevent UHPC’s thermal spalling; (b) PP fibres are more effective than PVA fibres in controlling thermal spalling; and (c) hybrid fibres (PP + steel fibres) are the most effective in terms of spalling control and residual strength. In general, other hybrid fibres are shown to be unable to control concrete spalling at temperatures around 400°C. As for the tensile strength in bending, long steel fibres have an edge over mixed steel fibres (with different lengths). Contrary to the compressive strength (that starts decreasing at 600°C), the tensile strength continues to increase above 600°C and starts decreasing at 800°C. As for bond performance, in the thermal range 25–1000°C, pullout tests were performed by using 12-mm deformed bars and three different values for the bonded length/bar diameter ratio (L/D = 2, 4 and 6). On the whole, the decay of bond strength with the temperature is similar to that of the compressive strength. Long steel fibres show higher bond strength, whereas mixed steel fibres offer advantages in other stages such as higher initial stiffness. Based on test data, empirical equations are proposed for the bond-slip law in a high-temperature environment.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110259"},"PeriodicalIF":4.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097261","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 performance of novel SC-FEDB and its application in RC frames","authors":"De-Bin Wang ,&nbsp;Guang Yang ,&nbsp;Zhi-Guo Sun ,&nbsp;Wen-Ming Wang ,&nbsp;Geng Min","doi":"10.1016/j.istruc.2025.110141","DOIUrl":"10.1016/j.istruc.2025.110141","url":null,"abstract":"<div><div>To enhance the energy dissipation capacity of traditional self-centering braces, a novel friction self-centering brace (SC-FEDB) with response amplification mechanism has been proposed. This paper delineates the fundamental structure and operational principles of the brace, while deriving both the theoretical restoring force model and amplification calculation formulas for deformation and load responses. Furthermore, low-cycle repeated loading tests were conducted to investigate its bearing capacity, residual deformation, energy dissipation, and stiffness variations at each stage; these experimental results were subsequently compared with the theoretical restoring force model. A simplified model of the SC-FEDB was developed using Abaqus software, followed by dynamic time history analysis of a RC frame structure incorporating the SC-FEDB to assess its seismic control efficacy. The findings indicate that the hysteretic curve of SC-FEDB is smooth and robust, exhibiting distinct flag-shaped characteristics alongside stable energy dissipation performance. By decreasing the initial amplification angle, significant improvements in both bearing capacity and energy dissipation capability were observed. Compared with traditional buckling-restrained braced (BRB) frame structures, the proposed brace structural system demonstrates superior performance in reducing key seismic response parameters, including inter-story drift angle, residual inter-story drift angle, and base shear force of the structure. As the initial amplification angle decreases, the SC-FEDB shows a significant force amplification phenomenon, with its output displacement significantly reduced, but the energy dissipation efficiency significantly improved. The seismic control effect of the SC-FEDB on the structure is more remarkable.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110141"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097324","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":"Exploration of the seismic behavior of full-scale steel frame with endplate connection based on component model","authors":"Shengcan Lu ,&nbsp;Huansen Chen ,&nbsp;Zhan Wang ,&nbsp;Minrong Wang","doi":"10.1016/j.istruc.2025.110245","DOIUrl":"10.1016/j.istruc.2025.110245","url":null,"abstract":"<div><div>With its stability and superior ductility for nonlinear deformation, steel frames with endplate connection are usually applied in high seismicity region. With the aim to investigate the response of rotational mechanical features to global steel frame and achieve high-efficiency computation of the frame behaviors, a full-scaled steel frame with endplate connection of low cyclic loading test were conducted. Moreover, the component method was applied to evaluate the rotational capacity of endplate connection on the frame, and verify the calculation accuracy through experiments results and ABAQUS results. 13 six-story frame models with different rotational mechanical features under 4 ground motions were performed to investigate the practicability of the analytical model and predict the seismic behaviors of the steel frame. The contribution of this paper is to reveal the mechanical properties and deformation capacity of the frame with various moment-rotation curves in static and dynamic states. This is a generalized approach that can be used to other connection types seismic analysis.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110245"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097329","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":"Data-driven prediction of load transfer function for high neck flexible flange bolts in lattice wind turbine towers","authors":"Hang Du ,&nbsp;Chuannan Xiong ,&nbsp;Kaoshan Dai ,&nbsp;Junlin Heng ,&nbsp;Yuxiao Luo ,&nbsp;Ke Fan ,&nbsp;Bin Wang ,&nbsp;Ji Li","doi":"10.1016/j.istruc.2025.110224","DOIUrl":"10.1016/j.istruc.2025.110224","url":null,"abstract":"<div><div>The load transfer function (LTF) of flange bolt connections is crucial for evaluating the fatigue life of lattice wind turbine towers. Traditional LTF methods face accuracy challenges due to larger flange sizes with increasing turbine hub heights. This study validates the Schmidt/Neuper method and introduces a machine learning (ML) approach to calculate bolt internal forces. After validating the finite element model (FEM) through static testing, the study compares the LTFs of integral flange connections and simplified models with the Schmidt/Neuper method, identifying its limitations. A parameter correlation analysis leads to the creation of a FEM database, from which various machine learning models: Linear Regression (LR), k-Nearest Neighbors (KNN), Support Vector Regression (SVR), Decision Tree (DT), Gaussian Process Regression (GPR), Random Forest (RF), CatBoost (CB), and XGBoost (XG) are developed and tested. A user-friendly graphical interface is provided. The finding reveals the limitations of Schmidt/Neuper method, mainly due to its assumption of a single bolt joint and neglecting load distribution, leading to inaccuracies. The ML approach improves LTF prediction accuracy, providing a more reliable method for fatigue life assessment in flange bolt connections.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110224"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097326","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":"Experimental study on seismic performance of precast high-strength RC beam-column joint with embedded channel steel and UHPC","authors":"Shujun Hu ,&nbsp;Hongwei Xu ,&nbsp;Sizhi Zeng ,&nbsp;Tao Chen ,&nbsp;Kang He","doi":"10.1016/j.istruc.2025.110235","DOIUrl":"10.1016/j.istruc.2025.110235","url":null,"abstract":"<div><div>To further improve the seismic performance, economic and seismic resilience of prefabricated reinforced concrete (RC) beam-column joints, an innovative prefabricated high-strength RC beam-column joint (PHBCJ) with ultra-high strength concrete (UHPC) and embedded channel steel has been developed, which integrates the 500 MPa high-strength rebar, 120 MPa UHPC and embedded channel steel (ECS). To evaluate its performance, one high-strength cast-in-place RC beam-column joint and four PHBCJ specimens with varying rebar strength, concrete strength and ECS, along with two repaired PHBCJ specimens, were tested under cyclic loading, simulating rare and ultimate seismic conditions. Finite element models were established and verified with test results. Key parameters such as failure modes, hysteresis curves, skeleton curves, secant stiffness, energy dissipation capacity and strain-displacement behavior were analyzed. The results indicate that the incorporating UHPC and ECS effectively prevents cracking occurs in the joint region, confining damage primarily to the beam ends. The PHBCJ with HRB500 rebar and ECS demonstrated superior bearing capacity and cost efficiency. Moreover, the seismic performance of PHBCJs with grouted sleeve connections between the precast upper and lower columns, combined with post-poured concrete in the joint region, closely resembled that of cast-in-place specimen. Additionally, the repaired joints exhibited nearly identical seismic performance to their pre-damage condition. In the PHBCJ with post-pored UHPC, damage was localized at the end of beam, reducing the affected area and severity, thereby enhancing repair efficiency and economic viability. Overall, the novel PHBCJ successfully meets the key design principles, including “strong joint weak component,” “strong column weak beam,” “strong shear weak bending,” and “plastic hinge relocation away from the column,” ensuring improved seismic performance and seismic resilience capacity, which align well with the seismic demands of modern structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110235"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097328","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":"Refined FE-based cross-section analysis for line element simulation of WAAM steel members considering anisotropy","authors":"Hao-Yi Zhang ,&nbsp;An-Rui Liang ,&nbsp;Si-Wei Liu ,&nbsp;Yao-Peng Liu ,&nbsp;Siu-Lai Chan","doi":"10.1016/j.istruc.2025.110236","DOIUrl":"10.1016/j.istruc.2025.110236","url":null,"abstract":"<div><div>Wire-arc additive manufacturing (WAAM) has emerged as a promising technique for fabricating large-scale 3D-printed steel structures. However, the development of its full potential is constrained by the current line element-based second-order analysis method for steel structures, which fails to account for the material anisotropy inherent in WAAM. This study addresses this limitation by reformulating the cross-sectional properties utilized in line elements, incorporating an anisotropic material model that accounts for the effect of the printing direction. A 2D finite element analysis (FEA) is employed for numerical solutions of the cross-sectional properties, which are then implemented into a 7-degrees-of-freedom (DOF) Timoshenko line element. The proposed method is validated through comparisons with benchmark results from sophisticated finite element analyses (SFEA). This research provides a novel approach to accurately model WAAM steel members in second-order analysis, which has been incorporated into the MSASect2 software for both research and educational purposes.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110236"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097323","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":"Cyclic loading behavior and restoring force model of disc-spring self-centering beam-column joints","authors":"Yi Ru ,&nbsp;Chao Dou ,&nbsp;Li-ji Huang ,&nbsp;Long-he Xu","doi":"10.1016/j.istruc.2025.110244","DOIUrl":"10.1016/j.istruc.2025.110244","url":null,"abstract":"<div><div>This study theoretically investigated a new type of prefabricated Disc spring Self-centering Steel beam-column Joints (DsSCSJs). It incorporates the disc-spring device to produce restoring force and web friction cover plates to provide energy dissipation capacity, while confining plastic damage primarily to the upper flange cover plates at the splicing connection of the main beams. The spliced beam segment rotates about the center of the upper flange cover plates, reducing the adverse impact of the \"beam elongation\" effect in traditional self-centering frames. Based on the previous cyclic loading tests of the joints, this paper mainly investigates the working mechanism and hysteretic performance of the new joint by using the verified finite element analysis (FEA). The effects of key factors on the hysteretic behavior and self-centering ability were explored, including disc-spring stiffness, web plate friction, flange cover plate thickness, bolt slip, and connection detailing. Subsequently, a moment-rotation restoring force model of the joint was established from theoretical derivations, with detailing suggestions proposed. The results showed that the finite element model and analysis were in good agreement with the test results, revealing its working mechanism and performance. The proposed theoretical restoring force model can accurately simulate the cyclic loading behavior of joints. A pin connection in the self-centering device results in lower stress concentrations and better self-centering ability in the DsSCSJ. To attain complete self-centering, the pre-compression bending moment produced by the disc spring should be greater than the friction moment and the plastic resistance moment of the beam flange cover plates. The residual deformation of the joints is primarily caused by the bolt slippage and possible local yielding at the beam-column connection, and consequently the self-centering ability of the DsSCSJ can be effectively improved by diminishing bolt slip and preventing the beam-column connection yielding by proper design and construction detailing.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110244"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097322","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}