Pub Date : 2024-05-09DOI: 10.1177/13694332241252273
Chien-Kuo Chiu, Hsin-Fang Sung, Jie-Ci Chou, Sharan Roy Choudhury
Transverse opening in the plastic hinge region of reinforced concrete (RC) beam is generally not recommended due to increased risk of shear failure rather than flexure or flexure-shear failure. However, in recent years, the actual pipeline configuration requirements have posed challenges in arranging such opening in the plastic hinge region of an RC beam member. To address this issue and propose design guidelines, this work examines the mechanical behavior of nine specimens subjected to cyclic loading. The test results are compared with the design methods suggested in other guidelines and research. Additionally, a set of design guidelines and novel reinforcement methods, utilizing Double-square hoop and U-shaped stirrups, are proposed and compared with traditional reinforcement methods for RC beams with circular openings. Three distinct regions for reinforcing beams with transverse circular openings are proposed based on their distance from the column support. In the first region, extending from three times the opening diameter to one beam depth (1H), the opening is reinforced with two inclined U-shaped stirrups on each side and double-square hoops on both faces. The second region (1H to 2H) utilizes one inclined U-shaped stirrup on each side, along with double-square hoops on both faces. Beyond twice the beam depth (2H) in the third region, the opening is reinforced solely with double-square hoops on both faces. The sets of design methods provide valuable insights for future design considerations.
一般不建议在钢筋混凝土（RC）梁的塑性铰区横向开孔，因为这会增加剪切破坏的风险，而不是弯曲或弯曲-剪切破坏的风险。然而，近年来，实际的管道配置要求给在钢筋混凝土梁构件的塑性铰区安排此类开口带来了挑战。为了解决这一问题并提出设计指南，这项工作研究了九个试样在循环荷载作用下的力学行为。测试结果与其他指南和研究中提出的设计方法进行了比较。此外，还针对带有圆形开口的 RC 梁提出了一套设计指南和新型加固方法（利用双方箍筋和 U 形箍筋），并与传统加固方法进行了比较。根据横向圆形开口梁与支柱支撑的距离，提出了三个不同的加固区域。在第一个区域，从开口直径的三倍延伸到一个梁深（1H），开口两侧各用两个倾斜的 U 形箍筋加固，两面用双方形箍筋加固。第二个区域（1H 至 2H）两侧各使用一个倾斜的 U 形箍筋，两面使用双方形箍筋。在第三个区域，超过两倍梁深（2H）后，开口只用两面的双方形箍筋加固。这几种设计方法为今后的设计考虑提供了宝贵的启示。
{"title":"Reinforcement methods of an reinforced concrete beam with the circular opening in the plastic hinge region under cyclic loading","authors":"Chien-Kuo Chiu, Hsin-Fang Sung, Jie-Ci Chou, Sharan Roy Choudhury","doi":"10.1177/13694332241252273","DOIUrl":"https://doi.org/10.1177/13694332241252273","url":null,"abstract":"Transverse opening in the plastic hinge region of reinforced concrete (RC) beam is generally not recommended due to increased risk of shear failure rather than flexure or flexure-shear failure. However, in recent years, the actual pipeline configuration requirements have posed challenges in arranging such opening in the plastic hinge region of an RC beam member. To address this issue and propose design guidelines, this work examines the mechanical behavior of nine specimens subjected to cyclic loading. The test results are compared with the design methods suggested in other guidelines and research. Additionally, a set of design guidelines and novel reinforcement methods, utilizing Double-square hoop and U-shaped stirrups, are proposed and compared with traditional reinforcement methods for RC beams with circular openings. Three distinct regions for reinforcing beams with transverse circular openings are proposed based on their distance from the column support. In the first region, extending from three times the opening diameter to one beam depth (1H), the opening is reinforced with two inclined U-shaped stirrups on each side and double-square hoops on both faces. The second region (1H to 2H) utilizes one inclined U-shaped stirrup on each side, along with double-square hoops on both faces. Beyond twice the beam depth (2H) in the third region, the opening is reinforced solely with double-square hoops on both faces. The sets of design methods provide valuable insights for future design considerations.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"6 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09DOI: 10.1177/13694332241252278
Tao Chen, Qiang Wang, Xiao-Jun Yao
Modal parameters are structural inherent characteristics that can be applied for revealing performance of railway bridges. Free vibration signals generated by a passage of train are commonly utilized to estimate the modal parameters of railway bridges due to their higher signal-to-noise ratios compared to random vibrations caused by ambient loads. However, since free vibration signals rapidly decay over time, the available free-vibration data is typically short-time. When using the fast Fourier transform-based spectral estimation method for modal identification from short-time vibration data, a phenomenon known as spectral leakage occurs, leading to miss-identification of some structural modes. In this study, the classical frequency domain decomposition (FDD) is improved for modal identification of railway bridges, in which the higher resolution auto-power spectral density (PSD) and cross-PSD functions are calculated through the autoregressive (AR) model-based method. The AR model-based method improves both the smoothness and resolution of the PSD functions compared to the fast Fourier transform technique. These AR model-based PSD functions are then employed in the FDD process to facilitate frequency and mode shape identification while avoiding spurious noise modes. The proposed eigenvalue fitting technique is subsequently utilized to estimate damping ratios. Numerical simulation data as well as vibration data from an actual bridge are analyzed to validate the proposed method, with a comparison made to the Welch’s PSD-based method. The results demonstrate that the modified FDD approach enables more effective identification of structural modes, even in the presence of closely-spaced modes.
模态参数是结构的固有特性，可用于揭示铁路桥梁的性能。与环境荷载引起的随机振动相比，火车通过时产生的自由振动信号具有更高的信噪比，因此通常用于估算铁路桥梁的模态参数。然而，由于自由振动信号会随时间迅速衰减，因此可用的自由振动数据通常都是短时数据。在使用基于快速傅立叶变换的频谱估计方法对短时振动数据进行模态识别时，会出现一种称为频谱泄漏的现象，导致对某些结构模态的识别错误。本研究改进了用于铁路桥梁模态识别的经典频域分解（FDD）方法，通过基于自回归（AR）模型的方法计算出分辨率更高的自功率谱密度（PSD）和交叉PSD函数。与快速傅立叶变换技术相比，基于 AR 模型的方法提高了 PSD 函数的平滑度和分辨率。这些基于 AR 模型的 PSD 函数随后被用于 FDD 流程，以促进频率和模态形状识别，同时避免杂散噪声模态。随后，利用所提出的特征值拟合技术来估算阻尼比。通过分析数值模拟数据以及实际桥梁的振动数据，验证了所提出的方法，并与基于韦尔奇 PSD 的方法进行了比较。结果表明，修改后的 FDD 方法能够更有效地识别结构模态，即使在模态间距很近的情况下也是如此。
{"title":"High-resolution frequency domain decomposition for modal analysis of bridges using train-induced free-vibrations","authors":"Tao Chen, Qiang Wang, Xiao-Jun Yao","doi":"10.1177/13694332241252278","DOIUrl":"https://doi.org/10.1177/13694332241252278","url":null,"abstract":"Modal parameters are structural inherent characteristics that can be applied for revealing performance of railway bridges. Free vibration signals generated by a passage of train are commonly utilized to estimate the modal parameters of railway bridges due to their higher signal-to-noise ratios compared to random vibrations caused by ambient loads. However, since free vibration signals rapidly decay over time, the available free-vibration data is typically short-time. When using the fast Fourier transform-based spectral estimation method for modal identification from short-time vibration data, a phenomenon known as spectral leakage occurs, leading to miss-identification of some structural modes. In this study, the classical frequency domain decomposition (FDD) is improved for modal identification of railway bridges, in which the higher resolution auto-power spectral density (PSD) and cross-PSD functions are calculated through the autoregressive (AR) model-based method. The AR model-based method improves both the smoothness and resolution of the PSD functions compared to the fast Fourier transform technique. These AR model-based PSD functions are then employed in the FDD process to facilitate frequency and mode shape identification while avoiding spurious noise modes. The proposed eigenvalue fitting technique is subsequently utilized to estimate damping ratios. Numerical simulation data as well as vibration data from an actual bridge are analyzed to validate the proposed method, with a comparison made to the Welch’s PSD-based method. The results demonstrate that the modified FDD approach enables more effective identification of structural modes, even in the presence of closely-spaced modes.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"32 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the engineering structures using circular steel tube (CST), the eccentric loading of CST members often occurs due to installation error and structural form. Existing research mainly focuses on the bearing resistance of circular steel pipes under the condition of eccentricity at one end. In practical application, both ends of CST members also may be eccentric. And with the increase in eccentricity, material yielding may occur prior to flexural buckling. So far, it’s lack of reports about the mechanical behavior of CST members subjected to eccentric loading at both ends and the boundary between material yielding and flexural buckling. This paper presents experimental, numerical and theoretical studies on bearing resistance of thin-walled circular steel tube with slenderness ratio of 30, 40 and 50, subjected to eccentric loading at one end and both ends, respectively. The study reveals a significant discrepancy in the prediction of bearing resistance for circular tubes subjected to eccentric loading at both ends according to existing design codes. Considering the synthesis of bending moment and deflection caused by eccentric loading at both ends, the calculation method of the bearing resistance based on flexural buckling of CST is established, which enhances the prediction accuracy of test verification. In addition, a theoretical boundary between the two failure modes appearing in CST members under eccentric loading at one and both end(s) - flexural buckling and reaching the material yielding strength - was established as dominated by the slenderness ratio and loading eccentricity.
{"title":"Investigation on bearing resistance of thin-walled circular steel tube subjected to eccentric loading","authors":"Zhenyun Tang, Jiayu Li, Mingqiao Wang, Xin Wang, Chunyi Yu, Zhenbao Li","doi":"10.1177/13694332241253395","DOIUrl":"https://doi.org/10.1177/13694332241253395","url":null,"abstract":"In the engineering structures using circular steel tube (CST), the eccentric loading of CST members often occurs due to installation error and structural form. Existing research mainly focuses on the bearing resistance of circular steel pipes under the condition of eccentricity at one end. In practical application, both ends of CST members also may be eccentric. And with the increase in eccentricity, material yielding may occur prior to flexural buckling. So far, it’s lack of reports about the mechanical behavior of CST members subjected to eccentric loading at both ends and the boundary between material yielding and flexural buckling. This paper presents experimental, numerical and theoretical studies on bearing resistance of thin-walled circular steel tube with slenderness ratio of 30, 40 and 50, subjected to eccentric loading at one end and both ends, respectively. The study reveals a significant discrepancy in the prediction of bearing resistance for circular tubes subjected to eccentric loading at both ends according to existing design codes. Considering the synthesis of bending moment and deflection caused by eccentric loading at both ends, the calculation method of the bearing resistance based on flexural buckling of CST is established, which enhances the prediction accuracy of test verification. In addition, a theoretical boundary between the two failure modes appearing in CST members under eccentric loading at one and both end(s) - flexural buckling and reaching the material yielding strength - was established as dominated by the slenderness ratio and loading eccentricity.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"1 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08DOI: 10.1177/13694332241252276
Jiannan Jiang, Yinhui Wang, Bo Yu, Bing Li, Jiaxing Ma
Under seismic loading, corroded reinforced concrete (RC) columns are prone to brittle shear failure, which poses a significant threat to existing structures. However, due to the mechanical defects and insufficient parameters included in the equations available in codes, the literature exhibits a lack of precision in predicting the shear strength of such columns. In this paper, a shear strength equation for the RC column was established based on the truss-arch model theory. On this basis, the effect of corrosion on key parameters such as the cross-sectional area of rebar, yield strength, compressive strength of concrete, and displacement ductility was fully considered to establish the shear strength equation of corroded RC columns. To assess the accuracy and applicability of the proposed equation, a database consisting of 215 specimen parameters was compiled. Comparative analyses were conducted with existing equations from the literature. The results indicate that the mean values and coefficient of variation for the ratio of calculated values to the tested values of the equation were 1.098 and 0.601, respectively, which proves the equation’s high computational accuracy and low dispersion. Consequently, the proposed equation offers a more effective calculation method for predicting and assessing the shear strength of corroded RC columns. This method holds significant potential for enhancing the resilience of structures in seismic-prone regions.
{"title":"A modified truss-arch model for shear strength evaluation of corroded reinforced concrete columns","authors":"Jiannan Jiang, Yinhui Wang, Bo Yu, Bing Li, Jiaxing Ma","doi":"10.1177/13694332241252276","DOIUrl":"https://doi.org/10.1177/13694332241252276","url":null,"abstract":"Under seismic loading, corroded reinforced concrete (RC) columns are prone to brittle shear failure, which poses a significant threat to existing structures. However, due to the mechanical defects and insufficient parameters included in the equations available in codes, the literature exhibits a lack of precision in predicting the shear strength of such columns. In this paper, a shear strength equation for the RC column was established based on the truss-arch model theory. On this basis, the effect of corrosion on key parameters such as the cross-sectional area of rebar, yield strength, compressive strength of concrete, and displacement ductility was fully considered to establish the shear strength equation of corroded RC columns. To assess the accuracy and applicability of the proposed equation, a database consisting of 215 specimen parameters was compiled. Comparative analyses were conducted with existing equations from the literature. The results indicate that the mean values and coefficient of variation for the ratio of calculated values to the tested values of the equation were 1.098 and 0.601, respectively, which proves the equation’s high computational accuracy and low dispersion. Consequently, the proposed equation offers a more effective calculation method for predicting and assessing the shear strength of corroded RC columns. This method holds significant potential for enhancing the resilience of structures in seismic-prone regions.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"41 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1177/13694332241252270
Linren Zhou, Ruitian Wanyan, Shaoji Li
The heat exchange between bridges and external environments is the primary cause of the temperature effect on bridges. The complexity of the two-phase (gas–solid) heat transfer mechanism, the diversity of the surface characteristics of bridge materials, and the uncertainties of the environment in which bridges are located make the numerical calculation of the heat exchange between bridges and external environments difficult. Several studies have been conducted by scholars around the world. In this work, the research on convective and radiative heat exchange between bridges and external environments is surveyed, analyzed, and summarized. The influencing factors and calculation methods of bridge temperature are examined, and the convective heat transfer and radiation mechanisms, theoretical calculations, and experimental measurement methods used to investigate the relation between bridges and external environments are summarized and analyzed. The value determination methods for convective heat transfer and radiation absorption coefficients in the calculation of the bridge temperature field are summarized. In addition, the problems and shortcomings of current research are evaluated, and future research directions are identified and discussed.
{"title":"Review on convective and radiation heat transfer between bridges and external environments","authors":"Linren Zhou, Ruitian Wanyan, Shaoji Li","doi":"10.1177/13694332241252270","DOIUrl":"https://doi.org/10.1177/13694332241252270","url":null,"abstract":"The heat exchange between bridges and external environments is the primary cause of the temperature effect on bridges. The complexity of the two-phase (gas–solid) heat transfer mechanism, the diversity of the surface characteristics of bridge materials, and the uncertainties of the environment in which bridges are located make the numerical calculation of the heat exchange between bridges and external environments difficult. Several studies have been conducted by scholars around the world. In this work, the research on convective and radiative heat exchange between bridges and external environments is surveyed, analyzed, and summarized. The influencing factors and calculation methods of bridge temperature are examined, and the convective heat transfer and radiation mechanisms, theoretical calculations, and experimental measurement methods used to investigate the relation between bridges and external environments are summarized and analyzed. The value determination methods for convective heat transfer and radiation absorption coefficients in the calculation of the bridge temperature field are summarized. In addition, the problems and shortcomings of current research are evaluated, and future research directions are identified and discussed.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"28 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140930558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1177/13694332241252281
Bo Hu, Hai-Bo Wang
Concrete-filled steel tubular (CFST) columns have been widely used in multi-story and high-rise frame structures. During the service period, they may suffer vehicle impact due to traffic accidents or terrorist attacks. This paper numerically evaluates the performance of CFST columns under vehicle impact and investigates the effects of carbon FRP (CFRP) wrapping arrangements on performance improvement of the columns. Before that, a numerical model was developed to simulate the responses of CFST columns without and with FRP wrapping under vehicle impact and post-impact axial compression, and then calibrated by reported tests. Evaluation results show that the performance of CSFT columns under vehicle impact is divided into five levels, i.e., no repair required, rapid repair required, minor repair needed, major repair needed, and replacement needed. The performance level decreases with the increase in the vehicle weight or speed and increases with the increase in the column diameter or steel tube thickness. The column height has little effects on the performance level. A higher axial load ratio, e.g., 0.5, might reduce the performance level. Besides, a CFST column tends to fail in flexure mode when hit by F800 medium truck, while it may fail in flexure & shear mode when hit by C2500 pickup truck. Investigation results indicate that FRP wrapping with each layer orientation of 90° (i.e., in the longitudinal direction) and 0° (i.e., in the hoop direction) present the best performance improvement for a CFST column possibly undergoing flexure & shear and flexure failure, respectively. The increase of the number of FRP layers effectively improves the performance levels of CFST columns but the excessive demand may be not economical. It is not necessary to employ an FRP wrapping range of 100% for improving the vehicular impact performance level of a CFST column to the expected one.
{"title":"Performance evaluation and FRP strengthening of concrete-filled steel tubular columns subjected to vehicle impact","authors":"Bo Hu, Hai-Bo Wang","doi":"10.1177/13694332241252281","DOIUrl":"https://doi.org/10.1177/13694332241252281","url":null,"abstract":"Concrete-filled steel tubular (CFST) columns have been widely used in multi-story and high-rise frame structures. During the service period, they may suffer vehicle impact due to traffic accidents or terrorist attacks. This paper numerically evaluates the performance of CFST columns under vehicle impact and investigates the effects of carbon FRP (CFRP) wrapping arrangements on performance improvement of the columns. Before that, a numerical model was developed to simulate the responses of CFST columns without and with FRP wrapping under vehicle impact and post-impact axial compression, and then calibrated by reported tests. Evaluation results show that the performance of CSFT columns under vehicle impact is divided into five levels, i.e., no repair required, rapid repair required, minor repair needed, major repair needed, and replacement needed. The performance level decreases with the increase in the vehicle weight or speed and increases with the increase in the column diameter or steel tube thickness. The column height has little effects on the performance level. A higher axial load ratio, e.g., 0.5, might reduce the performance level. Besides, a CFST column tends to fail in flexure mode when hit by F800 medium truck, while it may fail in flexure & shear mode when hit by C2500 pickup truck. Investigation results indicate that FRP wrapping with each layer orientation of 90° (i.e., in the longitudinal direction) and 0° (i.e., in the hoop direction) present the best performance improvement for a CFST column possibly undergoing flexure & shear and flexure failure, respectively. The increase of the number of FRP layers effectively improves the performance levels of CFST columns but the excessive demand may be not economical. It is not necessary to employ an FRP wrapping range of 100% for improving the vehicular impact performance level of a CFST column to the expected one.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"16 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1177/13694332241252275
Jincan Huang, Wei Hou, Zhiqiang Li, Yang Liu, Yixin Zhang
This study aims to investigate the influence of different surface treatments, including smooth interface, rough interface, anchor bolt connection, and epoxy bonding agent, on the shear resistance of Engineered Cementitious Composites (ECC)-concrete interface through bi-surface shear testing. The experimental results show that the interfacial shear strength between ECC and concrete is significantly enhanced by the implementation of the three interface treatment methods, as opposed to the smooth interface. Among these methods, the anchor bolt connection exhibits the greatest improvement in interfacial bonding performance. Notably, cohesive failure is observed in the anchor bolt connection method, while the other three methods result in adhesive failure, with only the anchor bolt connection method displaying ductile failure behavior. Following a comprehensive review of relevant studies and the outcomes of this experiment, three distinct interface bonding mechanisms were identified and the forces contributing to the bond were analyzed. Results indicated that the interfacial bond strength is notably influenced by the surface roughness. These research findings substantiate the viability of utilizing the anchor bolt connection method, particularly in applications where ductility requirements in the repair layer are essential for structural integrity.
{"title":"Enhancing the interfacial bond performance of engineered cementitious composites and concrete","authors":"Jincan Huang, Wei Hou, Zhiqiang Li, Yang Liu, Yixin Zhang","doi":"10.1177/13694332241252275","DOIUrl":"https://doi.org/10.1177/13694332241252275","url":null,"abstract":"This study aims to investigate the influence of different surface treatments, including smooth interface, rough interface, anchor bolt connection, and epoxy bonding agent, on the shear resistance of Engineered Cementitious Composites (ECC)-concrete interface through bi-surface shear testing. The experimental results show that the interfacial shear strength between ECC and concrete is significantly enhanced by the implementation of the three interface treatment methods, as opposed to the smooth interface. Among these methods, the anchor bolt connection exhibits the greatest improvement in interfacial bonding performance. Notably, cohesive failure is observed in the anchor bolt connection method, while the other three methods result in adhesive failure, with only the anchor bolt connection method displaying ductile failure behavior. Following a comprehensive review of relevant studies and the outcomes of this experiment, three distinct interface bonding mechanisms were identified and the forces contributing to the bond were analyzed. Results indicated that the interfacial bond strength is notably influenced by the surface roughness. These research findings substantiate the viability of utilizing the anchor bolt connection method, particularly in applications where ductility requirements in the repair layer are essential for structural integrity.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"118 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-27DOI: 10.1177/13694332241252274
Qiwu Wang, Fei Peng, Zhi Fang
The use of ultra-high-performance concrete (UHPC) allows for much smaller cross-sections compared to conventional reinforced concrete columns, which may make reinforced UHPC (R-UHPC) columns more susceptible to slenderness effects. Currently, there is no guideline in design standards for the slenderness limit of R-UHPC columns. This paper, therefore, attempts to develop a design provision for determining the slenderness limit of R-UHPC columns. Firstly, a numerical analytical model was proposed for predicting the load-deflection of R-UHPC columns under eccentric loading, which was validated by comparing its predictions with available experimental results from the available literature. Based on the validated model, a parametric study was then conducted to determine the key parameters affecting the slenderness limit of R-UHPC columns. It was found that the slenderness limit corresponding to the 5% strength reduction was sensitive to the ultimate compressive strain of UHPC, the tensile strength of UHPC, and the reinforcement ratio. On this basis, a design equation for the slenderness limit of R-UHPC columns in single curvature was statistically derived. Additionally, the slenderness limit for R-UHPC columns in non-sway frames was also proposed in a convenient form for design procedures.
{"title":"Slenderness limit for reinforced ultra-high-performance concrete columns","authors":"Qiwu Wang, Fei Peng, Zhi Fang","doi":"10.1177/13694332241252274","DOIUrl":"https://doi.org/10.1177/13694332241252274","url":null,"abstract":"The use of ultra-high-performance concrete (UHPC) allows for much smaller cross-sections compared to conventional reinforced concrete columns, which may make reinforced UHPC (R-UHPC) columns more susceptible to slenderness effects. Currently, there is no guideline in design standards for the slenderness limit of R-UHPC columns. This paper, therefore, attempts to develop a design provision for determining the slenderness limit of R-UHPC columns. Firstly, a numerical analytical model was proposed for predicting the load-deflection of R-UHPC columns under eccentric loading, which was validated by comparing its predictions with available experimental results from the available literature. Based on the validated model, a parametric study was then conducted to determine the key parameters affecting the slenderness limit of R-UHPC columns. It was found that the slenderness limit corresponding to the 5% strength reduction was sensitive to the ultimate compressive strain of UHPC, the tensile strength of UHPC, and the reinforcement ratio. On this basis, a design equation for the slenderness limit of R-UHPC columns in single curvature was statistically derived. Additionally, the slenderness limit for R-UHPC columns in non-sway frames was also proposed in a convenient form for design procedures.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"33 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140810229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Floating production storage and offloading systems (FPSOs) are gaining prominence in the offshore industry. FPSOs are generally designed to weathervane, necessitating surge vibration control for station keeping. Since the natural period of surge vibration is far higher than the dominant period of the input wave load, instead of supplemental damping, a high inertial device, such as the tuned mass damper inerter (TMDI), would be effective. This concept has hitherto not been investigated for the FPSO. A frequency domain formulation of the FPSO-TMDI system under wave force, considering interaction of the liquid cargo is presented. Utilizing Froude-Krylov theory, suitably modified to account for diffraction effects, wave force on the FPSO is obtained using field data from North Sea. TMDI parameters are optimized using Genetic Algorithm under different tank-fill conditions. The results demonstrate that the TMDI holds potential in providing an effective and robust performance in controlling the surge motion of FPSOs.
{"title":"Wave-induced vibration control of Floating production storage and offloading systems by tuned mass damper inerter","authors":"Nilarghya Sarkar, Sanjukta Chakraborty, Aparna (Dey) Ghosh","doi":"10.1177/13694332241247919","DOIUrl":"https://doi.org/10.1177/13694332241247919","url":null,"abstract":"Floating production storage and offloading systems (FPSOs) are gaining prominence in the offshore industry. FPSOs are generally designed to weathervane, necessitating surge vibration control for station keeping. Since the natural period of surge vibration is far higher than the dominant period of the input wave load, instead of supplemental damping, a high inertial device, such as the tuned mass damper inerter (TMDI), would be effective. This concept has hitherto not been investigated for the FPSO. A frequency domain formulation of the FPSO-TMDI system under wave force, considering interaction of the liquid cargo is presented. Utilizing Froude-Krylov theory, suitably modified to account for diffraction effects, wave force on the FPSO is obtained using field data from North Sea. TMDI parameters are optimized using Genetic Algorithm under different tank-fill conditions. The results demonstrate that the TMDI holds potential in providing an effective and robust performance in controlling the surge motion of FPSOs.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"14 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140629355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-17DOI: 10.1177/13694332241247917
Dong-Hui Yang, Yong-Chang Zhang, Xu Zheng, Ting-Hua Yi, Hong-Nan Li
Bearings are regarded as a crucial element that impacts the overall performance of the seismic analysis of bridges. The assessment of seismic performance in bridges heavily depends on the nonlinear features of bridge bearings. Therefore, it is essential to simulate the nonlinear mechanical behavior of bridge bearings to attain the required accuracy of seismic analysis. This paper examines the friction features of pot bearings using the Bouc-Wen hysteretic model, based on which a nonlinear model of pot bearings is proposed. The proposed model can rapidly and effectively analyze the nonlinear mechanical behaviors of bridge bearings under horizontal earthquakes by adequately simplifying the mechanical properties of these bearings. The accuracy of the model for horizontal seismic effects analysis is validated using a numerical simulation method. The simulation compares the nonlinear model seismic effects of the bearing with a linear-elastic model that ignores the bearing frictional effects under horizontal seismic action. The results demonstrated that in the proposed nonlinear model, the ratio of the composite bending moment and yield bending moment of the pier bottom section (demand capacity ratio) is lower than that of the linear elastic model, leading to a more accurate analysis of horizontal seismic effects and thus preventing overestimation of seismic consequences.
{"title":"Nonlinear model of bridge bearings considering friction effect under horizontal seismic action","authors":"Dong-Hui Yang, Yong-Chang Zhang, Xu Zheng, Ting-Hua Yi, Hong-Nan Li","doi":"10.1177/13694332241247917","DOIUrl":"https://doi.org/10.1177/13694332241247917","url":null,"abstract":"Bearings are regarded as a crucial element that impacts the overall performance of the seismic analysis of bridges. The assessment of seismic performance in bridges heavily depends on the nonlinear features of bridge bearings. Therefore, it is essential to simulate the nonlinear mechanical behavior of bridge bearings to attain the required accuracy of seismic analysis. This paper examines the friction features of pot bearings using the Bouc-Wen hysteretic model, based on which a nonlinear model of pot bearings is proposed. The proposed model can rapidly and effectively analyze the nonlinear mechanical behaviors of bridge bearings under horizontal earthquakes by adequately simplifying the mechanical properties of these bearings. The accuracy of the model for horizontal seismic effects analysis is validated using a numerical simulation method. The simulation compares the nonlinear model seismic effects of the bearing with a linear-elastic model that ignores the bearing frictional effects under horizontal seismic action. The results demonstrated that in the proposed nonlinear model, the ratio of the composite bending moment and yield bending moment of the pier bottom section (demand capacity ratio) is lower than that of the linear elastic model, leading to a more accurate analysis of horizontal seismic effects and thus preventing overestimation of seismic consequences.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"84 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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