Structures最新文献_第3页

Experimental study on acoustic emission damage in precast reinforced concrete interior joints containing disc springs 含碟形弹簧的预制钢筋混凝土内部接缝的声发射破坏实验研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107271

{"title":"Experimental study on acoustic emission damage in precast reinforced concrete interior joints containing disc springs","authors":"","doi":"10.1016/j.istruc.2024.107271","DOIUrl":"10.1016/j.istruc.2024.107271","url":null,"abstract":"<div><p>To address the inferior performance of precast reinforced concrete beam-column joints compared to cast-in-place joints during earthquakes, this study designed a precast concrete frame beam-column interior joint incorporating disc springs. The disc springs, installed based on grouted sleeve connections, aimed to enhance structural ductility and mitigate seismic forces on the joints. Five joints, including one cast-in-place joint, two ordinary precast joints, and two precast joints with disc springs, were tested quasi-statically and monitored using acoustic emission technology. The precast joints had axial compression ratios of 0.2 and 0.4. Parameters such as energy, count, and b-value from acoustic emission monitoring were analyzed. The Gaussian mixture model was employed for the clustering analysis of RA-AF parameters, and a damage model was developed to evaluate performance differences among the joints in the quasi-static tests. The results indicate that precast joints with the same axial compression ratio can achieve performance similar to cast-in-place joints, with more rapid damage development at higher axial compression ratios. Installing disc springs decelerates damage progression in the later stages of loading, maintaining joint integrity for a certain period even after reaching maximum load, thereby demonstrating improved ductility. At higher axial compression ratios, the b-value curve of joints with disc springs more closely resembles that of ordinary joints. Disc springs' positive effect is more pronounced in clustering analysis and damage models, such as their lower proportion of shear fractures.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233619","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}

引用次数: 0

Seismic resilience assessment of buildings with underground stories considering soil confinement

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107233

{"title":"Seismic resilience assessment of buildings with underground stories considering soil confinement","authors":"","doi":"10.1016/j.istruc.2024.107233","DOIUrl":"10.1016/j.istruc.2024.107233","url":null,"abstract":"<div><p>Many buildings are constructed with multiple underground stories, even if engineers do not commonly incorporate the underground stories in the seismic design. In addition, the common design practice is to neglect the effects of soil confinement on the performance of buildings under seismic loads. However, it is demonstrated that the seismic resilience performance of both low-rise and high-rise buildings, considering the couple effects of underground stories and soil confinement, needs a profound understanding. This paper aims to assess these mechanisms by performing shaking table tests and 3D numerical simulations on seven-story and fifteen-story structures, including several underground story percentages with variable support conditions (fixed, flexible) under different seismic motions. The experimental models were based on a precise geometric scaling factor (λ = 1:50) to represent the realistic performance of the buildings. Advanced numerical models were developed using PLAXIS 3D software to simulate the complex soil and structure with variable underground story percentages. The experimental and numerical outputs for scaled models were compared with the numerical real models in both support conditions (fixed, flexible), demonstrating that the applied shaking table may represent the complex mechanisms of the soil-structure coupling. The final objective was to compare the two types of buildings in terms of lateral displacement and shear force to demonstrate the impact of the soil-structure couple on the seismic resilience performance of these buildings. It was also shown that underground stories are more affected in cases of low-rise buildings if compared with high-rise buildings, whether fixed or flexible-base cases.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242802","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}

引用次数: 0

Flexural behavior of ultra-high-performance concrete (UHPC) encased concrete-filled steel tubular (CFST) beams

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107259

引用次数: 0

Experimental and numerical studies on the mechanical behavior of metallic connecting pieces in point-supported glass facades 点支承玻璃外墙金属连接件力学行为的实验和数值研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107294

{"title":"Experimental and numerical studies on the mechanical behavior of metallic connecting pieces in point-supported glass facades","authors":"","doi":"10.1016/j.istruc.2024.107294","DOIUrl":"10.1016/j.istruc.2024.107294","url":null,"abstract":"<div><p>Point-supported glass façades (PSGFs) have a wide application in gymnasia, airport terminals, and commercial buildings to achieve excellent balance between aesthetics and functionality. As the crucial components of PSGFs, the mechanical behavior of metallic connecting pieces directly impacts the security and stability of facades. This paper concentrates on the axial mechanical behavior of non-linear metallic connecting pieces used in PSGFs based on static and quasi-static tests. The effects of spider dimension, spider arm shape, and routel type on the mechanical behavior of connecting pieces are considered. Then, the refined finite element numerical models are established to perform parametric analyses. Results indicate that the spiders with cylindrical arms possess the most excellent load-bearing capacity, but the routel type has no effect on the bearing capacity of metallic connecting pieces. The deformation of test specimens under axial tensile load can be characterized by three stages, while just two stages under axial compressive load. There is no stiffness degradation of metallic connecting pieces under cyclic load, and their poor energy dissipation capacity in earthquakes can be inferred from the shape of load-deformation curves. Then, the stress distribution on the spider arm surface is obtained through theoretical calculation, so as to determine the most unfavorable section position of the spider arm under axial load. Finally, the simplified mechanical models of metallic connecting pieces under axial load are established according to their deformation features, which can be used for the numerical analysis of the point-supported glass facades.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233620","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}

引用次数: 0

Failure-mechanism for wind turbines supported by pile groups at the Kugino wind farm in the Kumamoto earthquake

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107201

{"title":"Failure-mechanism for wind turbines supported by pile groups at the Kugino wind farm in the Kumamoto earthquake","authors":"","doi":"10.1016/j.istruc.2024.107201","DOIUrl":"10.1016/j.istruc.2024.107201","url":null,"abstract":"<div><p>The Kugino wind farm at Japan was seriously damaged in the severe Kumamoto earthquake, characterizing as all three pile group cracks but only one tower buckling. This study aims to reveal the failure mechanism underlying such damage pattern through the Beam on Nonlinear Winkler Foundation (BNWF) analyses, where the soil-footing interaction is considered with a new q-z model (QzSimple6). It identifies three parameters in a hyperbolic function to match any desired modulus reduction curve, whereas adjusts the unloading-reloading curves iteratively with the Ishihara-Yoshida rule to achieve site-specific soil damping curve. The QzSimple6-based BNWF analyses quantitatively reproduces centrifuge test results of a pile group foundation system, and newly reveals the soil-footing interaction does not influence pile bending moments but reduces the point mass acceleration. A parametric study is conducted on the full BNWF model with identifying pile group supported wind turbine, but with scaling soil stiffness and strength. The thrust force is attracted from the aero-elastic analysis in OpenFAST and the free-filed seismic displacement are calculated with the site response analysis in OpenSees. The simulation shows consistency with site observations that the No.2 wind turbine tower is destined to buckling at the height of around 13.9 m due to the sudden reduction of tower thickness, while No.1 and No.3 towers could remain safe potentially because soil properties under them are softer than that under the No.2 tower. In contrast, all three pile groups are found to be cracked under the Kumamoto earthquake intensity since the pile bending moment relies on the footing rigidity rather than the footing-soil interaction.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352012424013535/pdfft?md5=112898c1950bcf9697ebb2f7071297a3&pid=1-s2.0-S2352012424013535-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study on bond-slip behaviors of CFRP sheet-Q690 high strength steel plate considering the effect of CFRP sheet thickness and bonding length

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107293

{"title":"Experimental study on bond-slip behaviors of CFRP sheet-Q690 high strength steel plate considering the effect of CFRP sheet thickness and bonding length","authors":"","doi":"10.1016/j.istruc.2024.107293","DOIUrl":"10.1016/j.istruc.2024.107293","url":null,"abstract":"<div><p>With the increasing application of carbon fiber reinforced polymer (CFRP) in steel structure engineering, the bond-slip behavior between the two has attracted much attention. Firstly, 18 sets of CFRP sheet-Q690qD high-strength steel double strap shear specimens were fabricated considering the effects of CFRP sheet thicknesses and bond length. Then, static and fatigue tests were conducted on them. Subsequently, based on the 3D-DIC acquisition technology, the bond-slip curves were obtained using the smoothing method and the fitting method respectively Finally, the three key parameters of <span><math><msub><mrow><mi>τ</mi></mrow><mrow><mi>max</mi></mrow></msub></math></span>, <span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>and <span><math><msub><mrow><mi>s</mi></mrow><mrow><mi>f</mi></mrow></msub></math></span> in the bifurcated model at each working condition were obtained. The experimental results indicated that the bond length was positively correlated with the static load ultimate strength, while the thickness of the CFRP sheet had less effect on the ultimate strength. The fatigue life of the specimen with a bond length of 40 mm under equal stress ratio fatigue loading was much higher than that of the specimens with bond lengths of 60 mm and 80 mm. It was found that the fitting method had better stability and accuracy in fitting the bond-slip curves of CFRP sheet-Q690qD high-strength steel specimens. The accuracy of the fitting maximum bond load was above 80 %, which can provide a relevant basis for the subsequent numerical simulation calculation.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242805","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}

引用次数: 0

Determination of mechanical properties of headed shear connectors in composite steel beams with precast concrete hollow core slabs: Experimental study

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107262

{"title":"Determination of mechanical properties of headed shear connectors in composite steel beams with precast concrete hollow core slabs: Experimental study","authors":"","doi":"10.1016/j.istruc.2024.107262","DOIUrl":"10.1016/j.istruc.2024.107262","url":null,"abstract":"<div><p>Precast concrete hollow core (PCHC) slabs are structural elements widely used in multistory long-span composite structures for their lightweight, cost-effectiveness, and guaranteed quality. In addition to ease of installation, PCHC slabs offer high acoustic and thermal insulation, as well as commendable fire resistance. In conventional composite beams with solid concrete slabs, the composite action is established via shear studs or other mechanical shear transfer mechanisms. Consequently, determining the shear strength and stiffness of the shear studs is necessary to quantify their composite behavior. However, few studies investigate the mechanical properties of the stud connectors in composite steel beams with PCHC slabs. This study addresses this gap by 11 full-scale push-out tests performed on specimens featuring 203- and 254-mm PCHC slabs connected to steel beam via 13- and 19-mm diameter connectors. The concrete compressive strength, slab thickness, shear stud diameter, and different shear stud layouts varied in the specimens. All specimens were tested to failure documenting the load-slip diagrams and the failure modes. Mechanical properties of the shear stud connectors were assessed based on the load-slip diagrams under monotonic and cyclic loadings. The result showed that the codified equations for estimating the shear capacity of studs in solid slabs underestimate the capacity of studs in PCHC slabs. Additionally, the shear capacity of shear stud connections was reduced about 15 % in the cyclic loading case compared to the monotonic.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242807","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}

引用次数: 0

Ductility of the double-sided bolted steel end-plate joint with column web openings under column loss scenario

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-16 DOI: 10.1016/j.istruc.2024.107264

{"title":"Ductility of the double-sided bolted steel end-plate joint with column web openings under column loss scenario","authors":"","doi":"10.1016/j.istruc.2024.107264","DOIUrl":"10.1016/j.istruc.2024.107264","url":null,"abstract":"<div><p>The load capacity and the rotational stiffness of the joints are the main parameters required in the design of steel-framed structures in a persistent design situation. In an accidental situation, high ductility of the joints is required to create and develop catenary action under the column loss scenario. Numerical parametric analyses of double-sided bolted steel end-plate joints were performed, focusing on the increase in the ductility of the joints by applying openings to the web of the column. The circular and longitudinal shapes of the openings were applied in two- and multi-configuration arrangements. Advanced 3D FEM models of the steel substructure were created using Abaqus software and validated versus the own experimental tests. The results demonstrate that application of column web openings in most cases allowed for a significant increase in ductility, which for steel joints means rotation capacity. In flush end-plate joints, an increase in ductility of joints was obtained in the range of 2–72 %. In extended end-plate joints, ductility improved in the 4–50 % range. An increase in the load capacity of the joints was obtained mainly in the case of extended end-plate joints, where a maximum improvement of 20 % was reached. The openings in the column web also change the failure mode of the joint, allowing the avoidance of premature destruction of the bolts. Some practical recommendations for choosing column openings in the design process are also presented.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242804","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}

引用次数: 0

A new cross section hypothesis-based approach for quantifying deployment characteristics of deployable inflatable structures 基于横截面假设的量化可展开充气结构展开特性的新方法

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-15 DOI: 10.1016/j.istruc.2024.107251

{"title":"A new cross section hypothesis-based approach for quantifying deployment characteristics of deployable inflatable structures","authors":"","doi":"10.1016/j.istruc.2024.107251","DOIUrl":"10.1016/j.istruc.2024.107251","url":null,"abstract":"<div><p>Deployable structures have demonstrated significant potential in various applications, such as space solar power stations and deep space communication due to their intuitive design, high folding efficiency, and compact launch volume. As their use becomes more prevalent, understanding the deployment mechanisms of these structures is increasingly essential. This study focuses on a specific type of deployable structures, known as inflatable membrane beams. We introduce a novel cross section hypothesis, proposing <em>a triangular shape</em> instead of the conventional <em>elliptical shape</em> to represent the cross section of an inflatable membrane beam undergoing bending deformation. This new hypothesis is then integrated into the theoretical framework. Based on this enhanced theoretical formulation, we develop two beam models, i.e., one with full enclosure and one with partial enclosure. These models allow us to analyze the effects of various parameters, including the beam deployment angle, the length and radius of the membrane beam, and the internal pressure of the beam, on its deployment moment. Extensive experimental analysis is conducted to deepen our understanding of the intrinsic relationships between these parameters and the deployment moment. The experimental results indicate that the new theoretical analysis offers superior prediction accuracy compared to the original theoretical model. The findings of this research provide theoretical support for the efficient and orderly folding, shape formation, and maintenance of large-scale deployable structures in orbit, contributing significantly to the future space missions and technologies.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233616","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}

引用次数: 0

Investigation on shear performance of sliding-type rapid segmental joints for shield tunnels 盾构隧道滑动式快速分段接头抗剪性能研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-09-15 DOI: 10.1016/j.istruc.2024.107275

{"title":"Investigation on shear performance of sliding-type rapid segmental joints for shield tunnels","authors":"","doi":"10.1016/j.istruc.2024.107275","DOIUrl":"10.1016/j.istruc.2024.107275","url":null,"abstract":"<div><p>This paper introduces a sliding-type rapid joint and investigates the joint's failure modes under compression-shear loading with a combination of numerical and experimental methods. The study analyzes the influence of axial force, arrangement methods, and segment thickness on the joint's shear resistance. Additionally, a detailed examination of stress distribution within the joints provides a deeper understanding of their mechanical behavior. The results reveal that four-stage exists in the shear-dislocation curve of joints, including static frictional stage, partial sliding stage, overall sliding stage, and descending stage. Increasing axial force enhances the joint's shear resistance, but excessively high axial forces raise the risk of shear failure in T-shaped components. Under the trans-arrangement, the sliding-type rapid segmental joint exhibits superior shear resistance, especially under high axial loads. The material strength of C-shaped components impacts the joint's shear resistance, and increasing segment thickness enhances the joint's shear resistance. Under reverse-radial shear conditions, the structure's shear capacity is not solely determined by the joint strength. Tangential shear occurs during the assembly process, emphasizing the need to avoid excessive assembly forces. The junction between the T-shaped structure and the joint panel is a vulnerable point for T-shaped components, and reinforcement by increasing size and thickness can prevent shear failure at this location.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233618","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}

引用次数: 0