Engineering Structures最新文献

{"title":"Effect of ICCP on conductivity properties of carbon fiber bundles and CFRCM","authors":"Jiaxin Hong,&nbsp;Dawei Zhang,&nbsp;Yewangzhi Tao,&nbsp;Jiarong Liu","doi":"10.1016/j.engstruct.2024.119311","DOIUrl":"10.1016/j.engstruct.2024.119311","url":null,"abstract":"<div><div>The effectiveness of carbon fabric reinforced cementitious matrix (CFRCM) in impressed current cathodic protection (ICCP) and structural strengthening (SS) of reinforced concrete (RC) structures has been verified. Meanwhile, due to the piezoresistive effect of carbon fibers, CFRCM has been developed as a self-monitoring sensor for structural health monitoring (SHM). However, the conductivity properties of CFRCM and carbon fiber under ICCP will be subject to performance degradation due to anodic reaction, which may have adverse effects on their role in SHM, and the degradation in seawater sea-sand (chlorine-containing environments) is still unknown. In this study, simulated ICCP tests were carried out on carbon fiber bundles in different solution environments and mortar environments to investigate the influences and mechanisms of different ICCP current densities, electrification durations, electrification environments, fiber lengths, and mortar types on conductivity properties of carbon fiber bundles and CFRCM. The prediction models for resistance were established based on a large number of experimental measurements. The results show that changes in resistance of carbon fiber bundles and CFRCM under ICCP exhibit two-stage characteristics of linear growth and rapid growth. The presence of chloride ions in seawater sea-sand environments can share polarization currents, reduce electrode potential, and slow down carbon fiber degradation. The degradation rates of carbon fiber bundles under four electrification environments, from fast to slow, are as follows: normal mortar, seawater sea-sand mortar, saturated Ca(OH)₂ solution, and saturated Ca(OH)₂ solution prepared with seawater. This study aims to promote the development of CFRCM materials with the multifunctional properties of ICCP-SS and SHM, and to achieve rational utilization of seawater and sea-sand.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119311"},"PeriodicalIF":5.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison study of seismic-tsunami performance for coastal bridges with different RC sacrificial shear keys","authors":"Heng Mei ,&nbsp;Anxin Guo","doi":"10.1016/j.engstruct.2024.119295","DOIUrl":"10.1016/j.engstruct.2024.119295","url":null,"abstract":"<div><div>Simple-support bridges are employed in offshore regions as integral component of coastal transportation networks. However, these bridges are vulnerable to the combined effects of earthquakes and ensuing tsunami waves due to weak lateral resistance. Reinforced concrete (RC) shear keys have been widely utilized to strengthen bridges by providing extra constraints to the superstructure. While the seismic performance of RC shear keys has been extensively studied, their effectiveness under the sequential action of both hazards remains seldom addressed yet. Therefore, this study aims to compare the seismic-tsunami response of bridges with different RC shear keys. To this regard, a novel envelope curve model was developed for the diagonal failure shear key, with emphasis on their distinct behaviors under seismic and tsunami impacts. OpenSees platform was employed, with natural ground motions and second-order solitary wave theory adopted for seismic and tsunami modeling, respectively. The shear key under each hazard was simulated using an Update Material approach to account for the distinct mechanical property. Subsequently, a parametric study was carried out to compare various factors, including shear key failure modes and strength, as well as wave conditions. The analysis result showed that the maximum strength of RC shear keys can significantly affect bridge performance, while the failure mode also contributes. In addition, the wave condition can largely affect the time-history and maximum deformation depending on water depths. Furthermore, the recommendations for shear key design against sequential seismic-tsunami hazards were provided.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119295"},"PeriodicalIF":5.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 reinforced concrete beams at low temperatures","authors":"Gu Xiang-Lin ,&nbsp;Wu Jie-Ying ,&nbsp;Yu Qian-Qian ,&nbsp;Liu Shuang ,&nbsp;Huang Qing-Hua","doi":"10.1016/j.engstruct.2024.119263","DOIUrl":"10.1016/j.engstruct.2024.119263","url":null,"abstract":"<div><div>This paper performs a comprehensive study on the flexural behavior of reinforced concrete (RC) beams at temperatures ranging from −180 ℃ to 20 ℃. Mechanical properties of steel reinforcements and concrete at low temperatures were first analyzed by tensile tests and uniaxial compressive tests, respectively. Empirical formulae for the mechanical properties of reinforcements and concrete at low temperatures were developed. Subsequently, four-point bending tests were conducted to investigate the bending capacities of RC beams (40 × 40 × 300 mm) at temperatures of 20 ℃, −40 ℃, −80 ℃, −120 ℃, −160 ℃, and −180 ℃. A finite element (FE) model of the RC beams at low temperatures was also established and verified by comparing with the test results. Based on the validated model, a parametric analysis was performed on full-scale RC beams, in consideration with the parameters of reinforcement ratio, compressive strengths of concrete, and the height of a beam. Finally, an analytical model was proposed for the bending capacity of an RC beam at temperatures from −180 ℃ to 20 ℃. Results showed that due to the increased yield strength of reinforcement and compressive strength of concrete, the yield strength and ultimate strength of an RC beam were also obviously increased at low temperatures. As the temperature decreased from 20 ℃ to −40 ℃, −80 ℃, −120 ℃, −160 ℃ and −180 ℃, the ultimate strength of an RC beam was increased by 26.5%, 39.4%, 91.5%, 112.3% and 160.6%, respectively.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119263"},"PeriodicalIF":5.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact resistance characteristics of pipeline system covered with W-shape elastic-porous metallic damper","authors":"Xin Xue,&nbsp;Shaoxiang Ge,&nbsp;Yilin Chen,&nbsp;Yuhan Wei,&nbsp;Juan Liao","doi":"10.1016/j.engstruct.2024.119302","DOIUrl":"10.1016/j.engstruct.2024.119302","url":null,"abstract":"<div><div>As a novel elastic-porous damping material fabricated through entangled wire mesh, W-shape elastic-porous metallic damper (W-EPMD) is considered an ideal damping element for coated pipeline system due to the micro dry friction between metal wires, which induces energy dissipation. The complex interwoven cellular formations of metallic wire mesh pose challenges in characterizing its dynamic characteristics. In this work, the dynamic properties of the pipeline system covered with W-EPMD under various impact conditions, including the acceleration response and impact isolation coefficient, were investigated by numerical simulations and experimental analysis. Constitutive models used to characterize the hysteresis behavior of W-EPMD were introduced, comprising Yeoh and Bergström-Boyce models, and parameter identification were conducted through quasi-static experiments. The reliability of the established numerical model was confirmed through drop impact experiments. The results demonstrate that there is a maximum discrepancy of 9.1 % between the simulation predictions and experimental results of the stress-strain curve. The impact isolation coefficient of the pipeline system covered with W-EPMD exhibits a fluctuating trend with the rise of the pulse peak, while the maximum compression of W-EPMD steadily increases. During the pipeline impact process, the increased density of W-EPMD reduces the impact resistance of the pipeline system, while excessively low density leads to over-compression and structural damage to W-EPMD. Furthermore, the discrepancy of the acceleration response between experimental and numerical results under various excitation signals remain within 6 %, demonstrating that the hysteresis model effectively characterizes the impact resistance characteristics of the pipeline system covered the W-EPMD.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119302"},"PeriodicalIF":5.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic sensitive failure mode in the progressive collapse of RC structures subjected to column removal scenarios","authors":"Luchuan Ding ,&nbsp;Jianbing Chen ,&nbsp;Robby Caspeele","doi":"10.1016/j.engstruct.2024.119301","DOIUrl":"10.1016/j.engstruct.2024.119301","url":null,"abstract":"<div><div>A series of structural collapse failures over the last decades have triggered an increasing research interest to identify ways to prevent progressive collapse when structures are subjected to local damage due to foreseen or unforeseen actions. Strong nonlinearities, dynamic effects, and system behavior should be taken into account in progressive collapse analyses. In order to avoid time-consuming nonlinear dynamic analyses, approaches using a dynamic increase factor or the energy-based method to the static pushdown curve are widely adopted. However, in this article it is shown that reinforce concrete (RC) structures may be evaluated as safe according to a static analysis but essentially unsafe when considering a dynamic analysis due to the dynamic snap-through behavior. This phenomenon results in a dynamic sensitive failure mode (DSFM) that should be identified in relation to progressive collapse analyses. Comparing with the static situation, the dynamic instability may result in a much more brittle failure mode in the dynamic situation due to the dynamic effects. Hence, the structure becomes sensitive to the dynamic effects and this may further lead to danger of brittle failure, which should be prevented in practice. An efficient method is proposed to approximately determine the load-displacement region where the DSFM occurs. This region is designated as the DSFM window. A two-linear-spring system, a RC beam-column substructure, and a RC frame structure are employed to illustrate the DSFM and verify the proposed method. The results demonstrate that the proposed approach can effectively determine the DSFM window for RC structures subjected to column removal scenarios.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119301"},"PeriodicalIF":5.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening, lifetime extension, and monitoring of a deficient steel–concrete composite roadway bridge using iron-based shape memory alloys","authors":"Jakub Vůjtěch ,&nbsp;Pavel Ryjáček ,&nbsp;Hessamoddin Moshayedi ,&nbsp;Jose Campos Matos ,&nbsp;Elyas Ghafoori","doi":"10.1016/j.engstruct.2024.119286","DOIUrl":"10.1016/j.engstruct.2024.119286","url":null,"abstract":"<div><div>This study presents an innovative application of smart metals for the prestressed strengthening of roadway bridges. The target structure is a steel–concrete composite bridge, in which poor construction practices cause nonlinear creep, excessive deflection, and crack growth. However, the high flood water level of the creek below the bridge limits the application of conventional strengthening solutions. Therefore, an innovative strengthening method using iron-based shape memory alloy (Fe-SMA) bars for the post-tensioning of bridge members was designed and employed. The study framework encompassed the design, laboratory examination, installation, and monitoring of Fe-SMA reinforcements. A finite-element simulation was used to estimate the effect of applied prestressing on the stress distribution of the structure. High-cycle fatigue tests of Fe-SMA bars with different types of connections at room temperature and –20 °C, were conducted to select the most reliable connections. A total of approximately 825 m of Fe-SMA bars with a diameter of 18 mm, comprising 68 Fe-SMA bars, were installed and activated. A wireless sensor monitoring system consisting of strain gauges, potentiometers, linear-variable differential transformer sensors, and thermocouples was utilized to measure the changes in strain and stress of the designed system under field conditions. The results revealed a prestress loss of 8.5 % owing to relaxation after six months, which match well to the values obtained by the laboratory tests. A second static loading test was conducted approximately six months after strengthening, and the results indicated a 9 % reduction in mid-span deflection and a remarkable 106 % reduction in average stresses in the lower flange at the mid-span of the beams. The results of monitoring the bridge for a duration longer than 6 months highlighted a significant decrease in the mid-span deflection and indicated the potential of Fe-SMAs for the lifetime extension of bridges.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119286"},"PeriodicalIF":5.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A cable-based tuned inerter damper for edgewise vibration control of the wind turbine blade","authors":"Jiawei Tang ,&nbsp;Qinlin Cai ,&nbsp;Kaoshan Dai ,&nbsp;Yangzhao Liu ,&nbsp;Junling Heng ,&nbsp;Yuxiao Luo","doi":"10.1016/j.engstruct.2024.119248","DOIUrl":"10.1016/j.engstruct.2024.119248","url":null,"abstract":"<div><div>As wind turbines grow larger, with longer blades aimed at enhancing wind energy conversion efficiency, the accompanying increase also results in heightened vibration, thereby posing safety challenges to the structure. The cable-based method, requiring limited stroke and installation space while ensuring satisfactory control performance, is an emerging vibration control strategy in these structures. This study evaluates the efficacy of a wind blade-suited cable-based tuned inerter damper (CTID) in mitigating edgewise vibrations. The CTID comprises inerter, damping, and spring elements, anchored at the hub and connected to the blade tip through a cable. First, the multi-degree-of-freedom blade-CTID coupled model is established. Subsequently, the wind load spectrum of the rotating blade is derived by considering the rotational Fourier spectrum of wind speeds acting on the blade. The pseudo excitation method facilitates stochastic response analysis under wind loads, while particle swarm optimization identifies optimal CTID parameters. The effectiveness of the CTID is numerically validated through a comparison with the conventional tuned mass damper, demonstrating its superior vibration mitigation performance and less on-demand stroke. The associated practical issues of the CTID are discussed, such as the axial cable force-induced instability and buckling issues. The numerical results of this study proved the effectiveness and practicability of rotating blade-suited CTID, providing a novel and promising vibration control strategy in limited-space structures.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119248"},"PeriodicalIF":5.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reference-free distributed monitoring of deflections in multi-span bridges","authors":"Dario Poloni ,&nbsp;Maurizio Morgese ,&nbsp;Chengwei Wang ,&nbsp;Todd Taylor ,&nbsp;Marco Giglio ,&nbsp;Farhad Ansari ,&nbsp;Claudio Sbarufatti","doi":"10.1016/j.engstruct.2024.119277","DOIUrl":"10.1016/j.engstruct.2024.119277","url":null,"abstract":"<div><div>The research presented herein pertains to developing a reference-free technique for monitoring bridge deflections under operational conditions. The method is based on monitoring the distributed strains along the length of bridges and employing the Inverse Finite Element Method (iFEM) to compute the deflection for the entire length of bridges. Distributed sensing of strains was achieved by a Brillouin Optical Time Domain Analysis system (BOTDA). The dynamic strains were then used in the iFEM algorithm to calculate the deflections of the structure. This approach computes structural displacements by a variational principle with minimal computational cost. Because of its independence from loads and material properties, the proposed methodology monitors the dynamic deflections during bridge routine traffic operations, and it is potentially viable for real-time monitoring. The approach is validated through two comprehensive case studies, including a laboratory experiment and a field application on a multi-span concrete bridge.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119277"},"PeriodicalIF":5.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 investigation on failure mechanism of stepped footings rocking on bedrock","authors":"Xingji Lu ,&nbsp;Jinhua Lu ,&nbsp;Fangjun Wang ,&nbsp;Haoyuan Gao","doi":"10.1016/j.engstruct.2024.119300","DOIUrl":"10.1016/j.engstruct.2024.119300","url":null,"abstract":"<div><div>The gravity pier with a multiple-step footing is a common substructure system in railway bridges in China, particularly on bedrock. Rocking of this system benefits its seismic performance during the earthquake, but the cantilever part of the stepped footing is vulnerable since it is loaded with a large eccentricity, which has not been well studied. The present paper investigates the failure mechanisms and load capacity of two-layer stepped footing, based on two quasi-static tests and twenty finite element analyses, where four parameters in the stepped footing are studied: the longitudinal reinforcement ratio, the shear span to depth ratio, the critical contact area ratio, and the aspect ratio. In all investigations, the bottom step of the footings fails in flexure. The two quasi-static tests reveal that with the increase of the longitudinal reinforcement ratio in the footing, the load capacity at peak increases, and the damages at the footing are slighter, whereas the damages at the pier body become severe. The finite element models of the two test specimens are first built, and the validations show the finite element results agree well with the test results. The remaining finite element analyses further find that increasing the critical contact area ratio, increasing the aspect ratio, or decreasing the shear span to depth ratio significantly reduces the extent of damage to the footing and increases the load capacities at different damage states. Moreover, the investigations also find damages at the pier body are influenced by the four parameters studied. As the longitudinal reinforcement ratio or critical contact area ratio increases, the damages at the pier body become severe. Whereas, increasing the shear span to depth ratio or the aspect ratio results in slighter damages at the pier body.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119300"},"PeriodicalIF":5.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress field models for discontinuity regions in steel-reinforced laminated glass","authors":"Mirko Pejatović,&nbsp;Robby Caspeele,&nbsp;Jan Belis","doi":"10.1016/j.engstruct.2024.119287","DOIUrl":"10.1016/j.engstruct.2024.119287","url":null,"abstract":"<div><div>This article presents the application of stress field models for strength prediction of discontinuity regions in steel-reinforced glass structures failing due to crushing of the glass and failure of stainless steel reinforcement. One of the main assumptions in the proposed modelling approach is that the structural laminated glass has similar compressive features as high-strength concrete within a framework of the stress field method. The paper initially introduces theoretical and experimental aspects and similarities between compressive behaviour of glass and high-strength concrete. Considerations on the compressive strength of laminated glass as well as the softening effect of cracks through the transverse strain factor are presented. The softening effect of cracks is investigated using the results of bending tests on beams and detailed digital image correlation (DIC) measurements. Finally, the proposed models are compared with results of tests on steel-reinforced glass members encompassing local compressive tests, bending tests and tests on beam-column connections. Additionally, the three groups of tests are numerically simulated using elastic-plastic stress fields (EPSF), through the finite element (FE) software EvalS for the automatic development of 2D stress fields. This numerical tool was originally developed for design and assessment of RC discontinuity regions. It is found that the numerical predictions are in a good agreement with test results. It is concluded that the stress fields may serve as a tool for the verification of a post-fracture limit state.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"323 ","pages":"Article 119287"},"PeriodicalIF":5.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}