Structures最新文献

{"title":"Theoretical study on the bond performance of embedded through-section reinforcing bar-to-concrete joints with localized debonding defects","authors":"Hong-Wei Wang ,&nbsp;Yan-Jie Wang ,&nbsp;Hong-Bo Liu ,&nbsp;Dong Ma ,&nbsp;Zhi-Min Wu ,&nbsp;Hui Jin ,&nbsp;Meng-Di Jia ,&nbsp;Xiaozhi Hu","doi":"10.1016/j.istruc.2025.108615","DOIUrl":"10.1016/j.istruc.2025.108615","url":null,"abstract":"<div><div>Embedded through-section (ETS) technique represents an efficient solution for strengthening existing reinforced concrete (RC) members, where steel or fibre-reinforced polymer (FRP) bars are inserted into predrilled holes and bonded to the concrete via adhesive. Recent experimental and theoretical studies on ETS bond interfaces have found that debonding defects may occur, in certain scenarios, in the construction process induced by air voids, poor grouting or partially cured adhesives, which negatively influences the bond behavior. Currently, little is known about the influence of localized debonding defects on the performance of ETS reinforcement bar-to- concrete joints at present. Therefore, this work attempts to propose a new analytical model that allows for studying the influence of localized debonding defects on the bond behavior of the ETS system. A cohesive zone model (CZM) with a trilinear bond-slip law is used to describe the nonlinearity of ETS reinforcement-to-concrete interfaces. Experimental investigations were conducted on both FRP and steel bars bonded in concrete using different adhesive types, defect lengths, and bond lengths. The solution proposed emphasised the key difference between “short” and “long” joints: short joints were characterized by a softening behavior in the load-slip curve regardless of debonding defects, while long joints exhibited two peak loads followed by a snap-back behavior in the presence of localized debonding defects. The results showed that the analytical predictions were in agreement with the test data, both revealing degradations of the load capacity of the joint with the increase of the ratio (<em>η</em>) between the debonded and the bonded area, particularly for short bonded joints. However, less sensitivity to the location of debonding defects was observed with minimal changes in the load degradation of both long and short joints. This paper facilitates a better understanding of the interfacial behavior of ETS reinforcement-to-substrate bonded joints with debonding defects.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108615"},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684249","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":"Empirical fragility quantification model of regional building portfolios considering optimized seismic intensity measures","authors":"Si-Qi Li","doi":"10.1016/j.istruc.2025.108688","DOIUrl":"10.1016/j.istruc.2025.108688","url":null,"abstract":"<div><div>Seismic fragility and hazard analyses of large-scale zonal building portfolios are fundamental for evaluating the earthquake performance of rural and urban structure clusters. Using probabilistic hazard and risk theory, an updated probability and risk model is developed to effectively display the seismic fragility features of regional buildings. However, the conventional definitions of vulnerability level and macroseismic intensity have features of fuzziness and randomness, resulting in relatively low quantitative accuracy of the fragility of structures in large-scale regions. This paper improves upon the traditional quantitative indicators of vulnerability level and develops an innovative scale to assess the four typical structure clusters in large-scale regions. The conventional macroseismic intensity measurements and logarithmic fitting model are updated using earthquake hazards, probability and reliability, the Bayesian model, and risk theory. The ground motion parameters and instrument seismic intensity measurements are auxiliary quantitative indicators. An improved vulnerability model of large-scale zonal structures considering updated intensity measures and an optimized nonlinear regression method is proposed. The correctness of the developed model is verified via actual seismic loss survey data (18,622.6086 ×10⁴ m²) from 57 powerful earthquakes that occurred in Xinjiang, China, from 1993 to 2023. By combining the vulnerability index model and data-cloud algorithm, a fragility curve and quantitative strip model for updating fragility databases considering large-scale zonal structure clusters are developed.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108688"},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684255","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 U-shaped steel-concrete composite beams with combined connector based on steel-bars truss","authors":"Jichun Liu ,&nbsp;Rui Cheng ,&nbsp;Yuhang Wang ,&nbsp;Xing Xu ,&nbsp;Chao Hu","doi":"10.1016/j.istruc.2025.108666","DOIUrl":"10.1016/j.istruc.2025.108666","url":null,"abstract":"<div><div>This paper discusses a new type of U-shaped steel-concrete composite beam (USCCB) with steel-bars truss connector to investigate its flexural behavior through experimental and theoretical analysis. Four-point bending tests were conducted on six specimens that were distinguished according to shear connectors: steel-bars truss, inverted U-shaped rebar, stud, and their combination. The test results show that USCCBs with inverted U-shaped rebar and the combined connector of steel-bars truss and inverted U-shaped rebar exhibit typical bending failure mode (ductile failure, <em>μ</em> &gt; 10), while that with studs and the combined connector of steel-bars truss and studs show certain brittle failure mode (<em>μ</em> &lt; 5). Specimen using only steel-bars truss connector has good ductility (<em>μ</em> &gt;10), but shows a marked insufficiency of shear interaction (<em>η</em> &lt; 1) due to the lowest bearing capacity, 510 kN. The adequate transverse reinforcement ratio (0.63 %) of the steel-bars truss and the triangular three-dimensional structure could effectively strengthen the anti-splitting ability of the concrete deck. USCCB with only steel-bars truss connector should be designed as partially composite beams, but some inverted U-shaped rebars can be arranged to enhance the shear resistance of the interface accordingly. Additionally, the failure of the stud connector is not conducive to the ductility of USCCB (<em>μ</em> &lt; 5). For structural safety, it is not recommended to use studs in whole or in part as the shear connectors of USCCB with full shear connection. The design methods according to full-section plasticity theory have a good prediction for the ultimate flexural capacity of USCCB.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108666"},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684252","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":"Investigation of window opening effects on blast resistance of square reinforced concrete panels via numerical and machine learning-based methods","authors":"Chaofeng Hua ,&nbsp;Hong Hao ,&nbsp;Jie Wei ,&nbsp;Yifei Hao","doi":"10.1016/j.istruc.2025.108712","DOIUrl":"10.1016/j.istruc.2025.108712","url":null,"abstract":"<div><div>To accommodate functional requirements in modern buildings, such as door and window installations, structural panels used as building facade often feature pre-fabricated openings. Studying the dynamic response of reinforced concrete (RC) structural panels with openings offers valuable insights into the effectiveness of design strategies. This paper aims to investigate the behaviour of two-way square RC panels with openings subjected to blast loads. Firstly, numerical simulations were conducted to analyse the blast-resistant response of two-way square RC panels with window openings. The results showed that the maximum displacement and damage of the panels with openings were significantly lower compared to solid panels. This reduction is primarily due to the fact that part of the blast waves passes through the opening, thereby decreasing the blast load on the panel. Furthermore, parametric studies indicated that panels with square opening at center exhibited a lower blast response as compared to openings of other shapes and at other locations. Finally, a predictive model for the normalized maximum displacement of RC panels with openings under blast loading was developed using machine learning techniques, providing a reliable tool for future design applications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108712"},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684341","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 behavior and strength evaluation of roof exterior beam-column joints with transverse beams on both sides: With eccentricity and slabs as variables","authors":"Su-Hyeon Jeong ,&nbsp;Yogi Cahyadi ,&nbsp;Min Jae Park ,&nbsp;Chang-Hwan Lee","doi":"10.1016/j.istruc.2025.108681","DOIUrl":"10.1016/j.istruc.2025.108681","url":null,"abstract":"<div><div>In this study, quasi-static cyclic tests were conducted to evaluate the behavior of roof exterior beam-column joints with non-seismic detailing. Four specimens were prepared, consisting of knee joints with transverse beams on both sides. The variables included eccentricity and the presence of slabs. All specimens exhibited joint shear failure and demonstrated significantly greater vulnerability during the opening action compared to the closing action. Specimens with slabs demonstrated increased strength and reduced cracking during the closing action. However, during the opening action, cracking around the bottom face of the beam increased, without notable changes in strength. When joint shear failure occurred, the predicted strength based on ASCE 41 differed from the experimental results. This discrepancy was attributed to the effects of the slabs and transverse beams, as well as the differences between the opening and closing actions, which were not considered in the standard. Based on the strength evaluation and a comprehensive analysis of various factors, recommendations for future codes and standards are proposed.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108681"},"PeriodicalIF":3.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684139","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":"Analysis of factors affecting structural durability based on reinforced concrete corrosion-induced cracking","authors":"Min Yuan ,&nbsp;Lu Zhang ,&nbsp;Jianqiao Wan ,&nbsp;Yu Li ,&nbsp;Wenqiang Xu ,&nbsp;Yongfeng Qi ,&nbsp;Zhiqiang Xie ,&nbsp;Wenbin Xu","doi":"10.1016/j.istruc.2025.108677","DOIUrl":"10.1016/j.istruc.2025.108677","url":null,"abstract":"<div><div>In harsh environments, the steel bars in reinforced concrete tend to corrode, reducing structural durability and functionality. Therefore, investigating the factors influencing concrete damage and cracking due to steel bar corrosion is crucial for analyzing structural durability. This study employs a phase field method (PFM) to model single steel bar corrosion, examining how corrosion morphology, cover thickness, concrete strength, heterogeneity, steel bar diameter, and aggregate content affect durability and failure patterns. The findings indicate that corrosion morphology and concrete heterogeneity significantly impact durability and failure, with increased non-uniform corrosion and heterogeneity leading to greater susceptibility to damage and cracking. While the impact of concrete strength is minor, the risk of cover failure rises as strength decreases. The influence of cover thickness and steel bar diameter on structural durability is small, with no significant effect on cover failure patterns. Although the random distribution of aggregates greatly affects durability and cover failure patterns, there is no significant correlation with aggregate content. This research provides essential references for the engineering design and durability analysis of concrete structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108677"},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643356","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":"Sensitivity analysis and multi-objective optimization of a vibration control system implemented in the base of multi-story structures","authors":"K.A. Kapasakalis ,&nbsp;A.E. Gkikakis ,&nbsp;E.J. Sapountzakis","doi":"10.1016/j.istruc.2025.108609","DOIUrl":"10.1016/j.istruc.2025.108609","url":null,"abstract":"<div><div>This study presents a systematic multi-objective design optimization procedure of a vibration control system (VCS) implemented in the base of multi-story structures for seismic protection. A multi-method sensitivity analysis is employed to identify the influence of each VCS component on the controlled structure’s seismic response and guide the optimization process. Subsequently, the Pareto fronts of the complete linear and nonlinear VCS are identified via the optimal trade-off between the base displacement demand and superstructure dynamic responses. Furthermore, several simplified VCS designs are explored, where parameters with negligible impact on the system performance are removed from the VCS configuration, yielding efficient resource allocation. It is concluded that the VCS is robust even without some of its components, showing minimal efficiency loss. Finally, the performance of the VCS is assessed with actual earthquake records and is compared to conventionally base-isolated structures, revealing alternative seismic protection approaches.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108609"},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643358","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":"Evaluation of experimental flexural behaviour and numerical parameters determination of bare foam and different types of foam filled sandwich panels","authors":"Sanjeev Saxena ,&nbsp;Anshul Badkul","doi":"10.1016/j.istruc.2025.108708","DOIUrl":"10.1016/j.istruc.2025.108708","url":null,"abstract":"<div><div>In the present study bare foam and three types (bondtite bonded, araldite bonded and metallic bonded) of metallic foam-filled sandwich panels were fabricated and experimentally tested under bending. The flexural strength, energy dissipation upto-maximum load, and maximum energy dissipation capacity of metallic bonded sandwich panel is far better than polymeric bonded sandwich panels. The magnitude of delamination is minimum in case of metallic bonded sandwich panels. The experimentally obtained flexural behaviour of bare foam and metallic foam-filled sandwich panels were also predicted using two-dimensional FEM models. Cohesive zone material modelling and cohesive elements were used to define delamination behaviour in-between the foam core and the two face sheets of sandwich panels. The adhesion properties of adhesive materials (bondtite, araldite, and metallic alloy) were experimentally determined using elcometer pull-off tests and it is used to define traction-separation laws in the modelling of delamination behaviour. The proposed numerical methodology is able to predict reasonably well the experimental flexural behaviour of foam-filled sandwich panels.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108708"},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684250","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":"Local buckling behaviour of the steel tube in elliptical CFST columns","authors":"Bo-Song Li,&nbsp;Yue-Ling Long,&nbsp;Xiang-Hua Yue","doi":"10.1016/j.istruc.2025.108648","DOIUrl":"10.1016/j.istruc.2025.108648","url":null,"abstract":"<div><div>Local buckling behaviour of the steel tube in elliptical concrete-filled steel tube (CFST) columns is investigated. A new model for local buckling of the steel tube in elliptical CFST columns under axial compression is proposed, assuming that the column ends are fixed and the concrete infilled is rigid. This proposed model involves the characteristics of elliptical section and account is taken of the influence of concrete infilled.The corresponding formula for elastic critical local buckling stress of the steel tube in elliptical CFST columns is derived. Subsequently, the calculated results by the proposed model are respectively compared with the results of tests and the previous theoretical model, which exhibits good agreement. Then the proposed formula is applied to investigate the local buckling behaviour of the steel tube in elliptical CFST columns. It is found that the local buckling behaviour of elliptical CFST columns is intermediate between that of circular CFST columns and that of rectangular CFST columns, and it is significantly influenced by both the relative thickness and aspect ratios (2<em>a</em>/2<em>b</em>), in which greater influence is found due to the relative thickness (2<em>b</em>/<em>t</em>_s). The critical local buckling stress of elliptical CFST columns decreases with aspect ratios (2<em>a</em>/2<em>b</em>) increasing. The critical local buckling stress of the steel tube in elliptical CFST columns significantly decreases with the relative thickness increasing. Besides, the concrete infilled can significantly increase the local buckling behaviour of elliptical hollow columns. Furthermore, the influence of the concrete infilled on the local buckling behaviour decreases with the relative thickness increasing while it increases with the aspect ratios increasing. Finally, reasonable ranges of the relative thickness are suggested for design of elliptical CFST columns.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108648"},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643105","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":"Performance, strategy, and evaluation of truss string structure based on active control","authors":"Ze Mo ,&nbsp;Binglin Lai ,&nbsp;Anping Wen ,&nbsp;Ganping Shu","doi":"10.1016/j.istruc.2025.108706","DOIUrl":"10.1016/j.istruc.2025.108706","url":null,"abstract":"<div><div>Active control is an intelligent regulation technology that can improve structural safety and enhance structural adaptability without changing the quality of the building structure. In order to make the truss string structure (TSS) adaptable to temporary loads during service, active control was introduced into TSS. In this study, an active control system including an actuating, a sensing, and a control device was established. The control effect of the active control system on the TSS under various temporary loads was studied experimentally, a control strategy for single-target monitoring of the TSS based on displacement state and stress state was proposed, and the evaluation method for active control of TSS was established by the control efficiency. The results show that the active control system can realize active control of the TSS with deformation as the target. Under symmetrical loads, monitoring any position can reduce the deflection of the TSS under the control strategy of displacement state and stress state, and the control efficiency is the same and can reach about 90 %. Under asymmetrical loads, the positions to be monitored under the control strategy of displacement state and stress state are different, and the control efficiency is higher under the control strategy of displacement state. However, due to the limitations of single-target monitoring, the control efficiency of TSS under asymmetrical loads is significantly lower than that under symmetrical load.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"75 ","pages":"Article 108706"},"PeriodicalIF":3.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643541","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}