F. Micozzi, L. Ragni, L. Gioiella, V. Quaglini, A. Dall’Asta
The λ-factors for stiffness and damping of rubber bearings should be experimentally assessed during the qualification process or deduced from tests performed on material specimens. Moreover, the λ-factors suggested in the informative annexes of EN 15129 and of EC8-part 2 can be also used as reference values. However, they are derived from outdated experimental campaigns and do not refer to all the sources of variability. In this paper, a statistical analysis on a significant set of rubber compounds, certified according to EN 15129 from different suppliers, is carried out to assess the current variability of the dynamic properties of such compounds. Different sources of variability may be identified by distinguishing between behavioural and environmental effects. For elastomeric bearings, especially high-damping rubber (HDR) ones, the main behavioural effects are strain amplitude, strain rate dependence, and cyclic degradation, whereas the environmental effects are due to temperature variation and ageing. All these sources of variability have been analysed in this paper. The results of the statistical analysis have been used to propose a new set of λ-factors for all the source of variability studied. Such new values have been compared with the ones suggested by the codes when available. The main inconsistencies found have been highlighted and commented in this paper. Finally, some considerations about the influence of such variability on the structural response of base-isolated structures have been drawn by focusing on both the isolation system and the superstructure.
{"title":"Variability of Dynamic Properties of Rubber Compounds for Elastomeric Bearings","authors":"F. Micozzi, L. Ragni, L. Gioiella, V. Quaglini, A. Dall’Asta","doi":"10.1155/2023/6638748","DOIUrl":"https://doi.org/10.1155/2023/6638748","url":null,"abstract":"The λ-factors for stiffness and damping of rubber bearings should be experimentally assessed during the qualification process or deduced from tests performed on material specimens. Moreover, the λ-factors suggested in the informative annexes of EN 15129 and of EC8-part 2 can be also used as reference values. However, they are derived from outdated experimental campaigns and do not refer to all the sources of variability. In this paper, a statistical analysis on a significant set of rubber compounds, certified according to EN 15129 from different suppliers, is carried out to assess the current variability of the dynamic properties of such compounds. Different sources of variability may be identified by distinguishing between behavioural and environmental effects. For elastomeric bearings, especially high-damping rubber (HDR) ones, the main behavioural effects are strain amplitude, strain rate dependence, and cyclic degradation, whereas the environmental effects are due to temperature variation and ageing. All these sources of variability have been analysed in this paper. The results of the statistical analysis have been used to propose a new set of λ-factors for all the source of variability studied. Such new values have been compared with the ones suggested by the codes when available. The main inconsistencies found have been highlighted and commented in this paper. Finally, some considerations about the influence of such variability on the structural response of base-isolated structures have been drawn by focusing on both the isolation system and the superstructure.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":" 19","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340372","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}
De-Cheng Feng, Wen-Jie Wang, Sujith Mangalathu, Zhen Sun
Condition rating of bridges is specified in many countries since it provides a basis for the decision-making of maintenance actions such as repair, strengthening, or limitation of passing vehicle weight. In practice, professional engineers check the textual description of damages to bridge members, such as girders, bearings, expansion joints, and piers that are acquired from periodic inspections, and then make a rating of the bridge condition. The task is time-consuming and labor-intensive due to the large amount of detailed data buried in the inspection reports. In this paper, a natural language processing- (NLP-) based machine learning (ML) approach is proposed for automated and fast bridge condition rating, which can efficiently extract the information of deficiencies in bridge members. The proposed approach involves three major steps, say, data repository establishment, NLP-based textual data processing, and ML-based bridge condition rating prediction. The data repository is established with the inspection reports of 263 concrete bridges, and in total there, are four condition levels for the bridges. Then, the NLP-based textual data processing approach is implemented to calculate the word frequency and the word clouds to visualize the characteristics of bridges in different condition levels. Finally, four typical ML techniques are adopted to generate the predictive model of the bridge condition rating. The results indicate that the NLP-based ML prediction model has an accuracy of 89% and is very efficient so that it can be used for large-scale applications such as condition rating for regional-level bridges.
{"title":"Condition Assessment of Highway Bridges Using Textual Data and Natural Language Processing- (NLP-) Based Machine Learning Models","authors":"De-Cheng Feng, Wen-Jie Wang, Sujith Mangalathu, Zhen Sun","doi":"10.1155/2023/9761154","DOIUrl":"https://doi.org/10.1155/2023/9761154","url":null,"abstract":"Condition rating of bridges is specified in many countries since it provides a basis for the decision-making of maintenance actions such as repair, strengthening, or limitation of passing vehicle weight. In practice, professional engineers check the textual description of damages to bridge members, such as girders, bearings, expansion joints, and piers that are acquired from periodic inspections, and then make a rating of the bridge condition. The task is time-consuming and labor-intensive due to the large amount of detailed data buried in the inspection reports. In this paper, a natural language processing- (NLP-) based machine learning (ML) approach is proposed for automated and fast bridge condition rating, which can efficiently extract the information of deficiencies in bridge members. The proposed approach involves three major steps, say, data repository establishment, NLP-based textual data processing, and ML-based bridge condition rating prediction. The data repository is established with the inspection reports of 263 concrete bridges, and in total there, are four condition levels for the bridges. Then, the NLP-based textual data processing approach is implemented to calculate the word frequency and the word clouds to visualize the characteristics of bridges in different condition levels. Finally, four typical ML techniques are adopted to generate the predictive model of the bridge condition rating. The results indicate that the NLP-based ML prediction model has an accuracy of 89% and is very efficient so that it can be used for large-scale applications such as condition rating for regional-level bridges.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"114 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818385","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}
Vehicle load estimation and health monitoring of bridges are of great importance for the health monitoring of bridge structure under vehicle loads. Traditional methods for the estimation of vehicle load require the positions of the vehicles. The vehicle position tracking is generally conducted in offline manner and requires the installation of additional sensors. To resolve these problems, we developed a Bayesian probabilistic approach for the online estimation of vehicle loads, vehicle positions, and structural parameters for bridges. The crux is to model the vehicle load vector as a modulated filtered Gaussian white noise due to the fact that the vehicle-bridge interaction forces are in essence the responses of the vehicle-bridge coupled system under the excitation of the road roughness described by Gaussian random field and the constant vehicle weights. Furthermore, the vehicle speed vector is introduced to track the unknown positions of vehicles. There are three appealing features in this approach. First, it allows the simultaneous estimation of vehicle loads, vehicle positions, and structural parameters in an online manner. Second, this method allows for time-varying vehicle speed tracking. Third, the proposed method is applicable to the case with multiple vehicles. Examples for the case where single/multiple vehicles pass across bridges with uniform speeds/variable speeds are presented to demonstrate the feasibility of the proposed method for vehicle load estimation, vehicle position tracking, and bridge structural identification using only strain measurements.
{"title":"Bayesian Vehicle Load Estimation, Vehicle Position Tracking, and Structural Identification for Bridges with Strain Measurement","authors":"Ka-Veng Yuen, Hou-Zuo Guo, He-Qing Mu","doi":"10.1155/2023/4752776","DOIUrl":"https://doi.org/10.1155/2023/4752776","url":null,"abstract":"Vehicle load estimation and health monitoring of bridges are of great importance for the health monitoring of bridge structure under vehicle loads. Traditional methods for the estimation of vehicle load require the positions of the vehicles. The vehicle position tracking is generally conducted in offline manner and requires the installation of additional sensors. To resolve these problems, we developed a Bayesian probabilistic approach for the online estimation of vehicle loads, vehicle positions, and structural parameters for bridges. The crux is to model the vehicle load vector as a modulated filtered Gaussian white noise due to the fact that the vehicle-bridge interaction forces are in essence the responses of the vehicle-bridge coupled system under the excitation of the road roughness described by Gaussian random field and the constant vehicle weights. Furthermore, the vehicle speed vector is introduced to track the unknown positions of vehicles. There are three appealing features in this approach. First, it allows the simultaneous estimation of vehicle loads, vehicle positions, and structural parameters in an online manner. Second, this method allows for time-varying vehicle speed tracking. Third, the proposed method is applicable to the case with multiple vehicles. Examples for the case where single/multiple vehicles pass across bridges with uniform speeds/variable speeds are presented to demonstrate the feasibility of the proposed method for vehicle load estimation, vehicle position tracking, and bridge structural identification using only strain measurements.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"50 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136234551","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}
Chien-Liang Lee, Yung-Tsang Chen, Ray Kai Leung Su, Yen-Po Wang
The vibration responses of tall flexible tool (or equipment) platforms subjected to floor excitations at the platform base are considered more crucial than those of the short ones. This study examined the microvibration control performance of the proposed active piezoelectric mass damper (APMD) or driver for tall platforms subjected to internal automated guided vehicle- (AGV-) induced floor vibrations with larger intensity and broader bandwidth in liquid-crystal-display (LCD) fabrication factories (fabs). The APMD did not require auxiliary spring and damping elements to tune the natural frequency and reduce the stroke of the mass block as required by typical active tuned mass dampers (ATMDs). The motion equation of the proposed analytical model including a continuous three-span beam (or floor) system and an active-controlled tool platform under the action of the AGV moving forces was derived. The APMD, consisting of piezoelectric stacks and a mass block, was installed on the platform subjected to the base rotation excitation, which could be attributed to the uneven vertical floor vibrations induced by AGVs. Moreover, the direct output feedback control algorithm was adopted to determine the optimal feedback gain matrix for calculating the active control force. Time history analyses of the continuous beam-platform model under different AGV weights moving at the same speed were performed, and the corresponding velocity vibration spectra of the floor and platform were further obtained through one-third octave band spectrum analysis. Numerical simulation results revealed that the microvibrations of the platform without APMD generally exceed the VC-A level regardless of the AGV weight. Significant reductions of over 90% on the platform microvibrations could be achieved after the platform was implemented with the APMD, and vibrations met the desired vibration limit (VC-B). Moreover, the APMD exhibits comparable microvibration control performance to the ATMD and requires less mass of the mass block, stroke, and applied voltage under the same active control force. In real-life high-tech production fabs, AGV-induced platform microvibrations occur all the time; therefore, the proposed APMD with less power consumption could be an economical and feasible approach for persistent microvibration control of tall platforms in LCD fabs.
{"title":"Active Microvibration Control of Tool Platforms Installed on the Floors Subjected to Moving Vehicles in Industrial Factories","authors":"Chien-Liang Lee, Yung-Tsang Chen, Ray Kai Leung Su, Yen-Po Wang","doi":"10.1155/2023/2077180","DOIUrl":"https://doi.org/10.1155/2023/2077180","url":null,"abstract":"The vibration responses of tall flexible tool (or equipment) platforms subjected to floor excitations at the platform base are considered more crucial than those of the short ones. This study examined the microvibration control performance of the proposed active piezoelectric mass damper (APMD) or driver for tall platforms subjected to internal automated guided vehicle- (AGV-) induced floor vibrations with larger intensity and broader bandwidth in liquid-crystal-display (LCD) fabrication factories (fabs). The APMD did not require auxiliary spring and damping elements to tune the natural frequency and reduce the stroke of the mass block as required by typical active tuned mass dampers (ATMDs). The motion equation of the proposed analytical model including a continuous three-span beam (or floor) system and an active-controlled tool platform under the action of the AGV moving forces was derived. The APMD, consisting of piezoelectric stacks and a mass block, was installed on the platform subjected to the base rotation excitation, which could be attributed to the uneven vertical floor vibrations induced by AGVs. Moreover, the direct output feedback control algorithm was adopted to determine the optimal feedback gain matrix for calculating the active control force. Time history analyses of the continuous beam-platform model under different AGV weights moving at the same speed were performed, and the corresponding velocity vibration spectra of the floor and platform were further obtained through one-third octave band spectrum analysis. Numerical simulation results revealed that the microvibrations of the platform without APMD generally exceed the VC-A level regardless of the AGV weight. Significant reductions of over 90% on the platform microvibrations could be achieved after the platform was implemented with the APMD, and vibrations met the desired vibration limit (VC-B). Moreover, the APMD exhibits comparable microvibration control performance to the ATMD and requires less mass of the mass block, stroke, and applied voltage under the same active control force. In real-life high-tech production fabs, AGV-induced platform microvibrations occur all the time; therefore, the proposed APMD with less power consumption could be an economical and feasible approach for persistent microvibration control of tall platforms in LCD fabs.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"63 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136234415","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}
Yang Yang, Zhewei Wang, Bing Xian, Hwa Kian Chai, Zhou Yu, Yao Zhang, Tao Zhu
In recent times, there has been a notable increase in the quantity of high-rise buildings, attributed to the swift advancements in both economic growth and construction technology. Assessing the structural integrity of high-rise buildings is important to ensure their safe operation. However, existing structural health monitoring methods typically require a baseline, involving either the measured dynamic and static responses from an intact structure or the finite element (FE) model corresponding to an undamaged state. These prerequisites are often challenging to acquire in practical scenarios. This study introduces a novel baseline-free method for detecting reduction in the lateral stiffness of high-rise buildings. The method is based on the statistical moment curvature (SMC) concept, determined through applying central difference to the second-order statistical moment of displacement. Initially, theoretical formulas were derived to demonstrate the viability of utilizing SMC for identifying reduction in the lateral stiffness of high-rise buildings. Subsequently, a FE model of a representative high-rise building was constructed to validate the proposed approach and assess its sensitivity, where different structural types and noise levels were considered. Lastly, a field test was conducted on a 33-story shear wall structure to provide additional validation for the proposed method. The results confirmed its effectiveness in accurately detecting reduction in the lateral stiffness of high-rise building. It offers two primary benefits: firstly, it obviates the need for a baseline, rendering it more convenient and applicable in real-world scenarios; secondly, its heightened sensitivity to sudden drops in lateral stiffness allows for early-stage detection of structural damage.
{"title":"Baseline-Free Detection Method for Change of Lateral Stiffness of High-Rise Building Based on Statistical Moment Curvature","authors":"Yang Yang, Zhewei Wang, Bing Xian, Hwa Kian Chai, Zhou Yu, Yao Zhang, Tao Zhu","doi":"10.1155/2023/4373174","DOIUrl":"https://doi.org/10.1155/2023/4373174","url":null,"abstract":"In recent times, there has been a notable increase in the quantity of high-rise buildings, attributed to the swift advancements in both economic growth and construction technology. Assessing the structural integrity of high-rise buildings is important to ensure their safe operation. However, existing structural health monitoring methods typically require a baseline, involving either the measured dynamic and static responses from an intact structure or the finite element (FE) model corresponding to an undamaged state. These prerequisites are often challenging to acquire in practical scenarios. This study introduces a novel baseline-free method for detecting reduction in the lateral stiffness of high-rise buildings. The method is based on the statistical moment curvature (SMC) concept, determined through applying central difference to the second-order statistical moment of displacement. Initially, theoretical formulas were derived to demonstrate the viability of utilizing SMC for identifying reduction in the lateral stiffness of high-rise buildings. Subsequently, a FE model of a representative high-rise building was constructed to validate the proposed approach and assess its sensitivity, where different structural types and noise levels were considered. Lastly, a field test was conducted on a 33-story shear wall structure to provide additional validation for the proposed method. The results confirmed its effectiveness in accurately detecting reduction in the lateral stiffness of high-rise building. It offers two primary benefits: firstly, it obviates the need for a baseline, rendering it more convenient and applicable in real-world scenarios; secondly, its heightened sensitivity to sudden drops in lateral stiffness allows for early-stage detection of structural damage.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"97 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513759","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}
Jijun Wang, Xiao Wei, Weidong Wang, Jin Wang, Jun Peng, Sicheng Wang, Qasim Zaheer, Jia You, Jianping Xiong, Shi Qiu
Terrestrial laser scanning (TLS) technology has the advantages of wide range, high efficiency, and low cost in spatial information collection, so it is widely used in infrastructure monitoring and measurement. During TLS application, the registration and positioning of the point cloud have a direct impact on the quality of the data and the validity of the results. The linear distribution of the tunnel structure and the lack of significant features present challenges in the registration and positioning of 3D point clouds in railway tunnels. The commonly used registration methods are difficult to achieve high registration accuracy and are prone to propagation errors, which reduce the accuracy and effectiveness of results. To achieve accurate registration and positioning of multistation clouds in railway tunnels, we propose a coordinate-based global registration method. To determine the coordinates of scan points in the reference coordinate system and the direction of the reference coordinate system, a few fixed control points are used during the data collection stage. Consequently, each station cloud can be precisely positioned and automatically registered in the reference coordinate system without accumulating or propagating errors. In addition, the coordinate-based registration method eliminates the introduction of errors due to artificial target setting and feature point extraction, as well as the problem of accurately positioning the entire point cloud in the reference coordinate system, thereby enhancing the accuracy, efficiency, and automation levels of cloud registration. The experiment demonstrates that the coordinate-based global registration method is robust and applicable in complex scenes, and it is suitable for the accurate positioning and registration of multistation clouds in linear and curved railway tunnels. The coordinate-based registration method reduces the amount of error in the global registration link by 65% when compared to the point-based registration method, and the point cloud accuracy has reached fine registration, ensuring that fine-grained inverse modeling of the tunnel structure can be performed.
{"title":"A Multistation 3D Point Cloud Automated Global Registration and Accurate Positioning Method for Railway Tunnels","authors":"Jijun Wang, Xiao Wei, Weidong Wang, Jin Wang, Jun Peng, Sicheng Wang, Qasim Zaheer, Jia You, Jianping Xiong, Shi Qiu","doi":"10.1155/2023/6705090","DOIUrl":"https://doi.org/10.1155/2023/6705090","url":null,"abstract":"Terrestrial laser scanning (TLS) technology has the advantages of wide range, high efficiency, and low cost in spatial information collection, so it is widely used in infrastructure monitoring and measurement. During TLS application, the registration and positioning of the point cloud have a direct impact on the quality of the data and the validity of the results. The linear distribution of the tunnel structure and the lack of significant features present challenges in the registration and positioning of 3D point clouds in railway tunnels. The commonly used registration methods are difficult to achieve high registration accuracy and are prone to propagation errors, which reduce the accuracy and effectiveness of results. To achieve accurate registration and positioning of multistation clouds in railway tunnels, we propose a coordinate-based global registration method. To determine the coordinates of scan points in the reference coordinate system and the direction of the reference coordinate system, a few fixed control points are used during the data collection stage. Consequently, each station cloud can be precisely positioned and automatically registered in the reference coordinate system without accumulating or propagating errors. In addition, the coordinate-based registration method eliminates the introduction of errors due to artificial target setting and feature point extraction, as well as the problem of accurately positioning the entire point cloud in the reference coordinate system, thereby enhancing the accuracy, efficiency, and automation levels of cloud registration. The experiment demonstrates that the coordinate-based global registration method is robust and applicable in complex scenes, and it is suitable for the accurate positioning and registration of multistation clouds in linear and curved railway tunnels. The coordinate-based registration method reduces the amount of error in the global registration link by 65% when compared to the point-based registration method, and the point cloud accuracy has reached fine registration, ensuring that fine-grained inverse modeling of the tunnel structure can be performed.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079957","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}
Chien-Chou Chen, Wen-Hwa Wu, Yi-Pei Ko, Gwolong Lai
To assess the applicability of the tension estimation method using local vibration measurements in a thorough manner, this research work is devoted to systematically investigate the appropriate covering ranges of measurements for different cables. Four cables of three cable-stayed bridges are deliberately chosen to cover a wide range of the cable slenderness parameter. Numerical analyses with finite element models and field validations with real measurements are conducted for these stay cables to demonstrate that the covering range of local measurements can be undoubtedly reduced with the increase of cable slenderness. For a relatively short cable with the slenderness parameter at the order of 4000, the adoption of 1/3 coverage is sufficient to keep a high-level accuracy with at most 1% of error. Besides, 1/4, 1/6, and 1/7 coverages are found adequate to maintain the same level of accuracy for longer cables with the slenderness parameter at the orders of 30000, 55000, and 80000, respectively. With the solid validations presented in the current study, the covering range of the cable for this simplified method employing local vibration measurements can be confidently reduced to greatly alleviate the expense and hard work of sensor installation near the high end.
{"title":"Extensive Field Validations and Corresponding Numerical Investigations for a Cable Tension Estimation Method Based on Local Vibration Measurements","authors":"Chien-Chou Chen, Wen-Hwa Wu, Yi-Pei Ko, Gwolong Lai","doi":"10.1155/2023/9691363","DOIUrl":"https://doi.org/10.1155/2023/9691363","url":null,"abstract":"To assess the applicability of the tension estimation method using local vibration measurements in a thorough manner, this research work is devoted to systematically investigate the appropriate covering ranges of measurements for different cables. Four cables of three cable-stayed bridges are deliberately chosen to cover a wide range of the cable slenderness parameter. Numerical analyses with finite element models and field validations with real measurements are conducted for these stay cables to demonstrate that the covering range of local measurements can be undoubtedly reduced with the increase of cable slenderness. For a relatively short cable with the slenderness parameter at the order of 4000, the adoption of 1/3 coverage is sufficient to keep a high-level accuracy with at most 1% of error. Besides, 1/4, 1/6, and 1/7 coverages are found adequate to maintain the same level of accuracy for longer cables with the slenderness parameter at the orders of 30000, 55000, and 80000, respectively. With the solid validations presented in the current study, the covering range of the cable for this simplified method employing local vibration measurements can be confidently reduced to greatly alleviate the expense and hard work of sensor installation near the high end.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135767416","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}
Mao Ye, Jin Jiang, Jingya Zhou, Wuliang Zhang, Baotao Huang, Ming Wu
Energy dissipation damping technology is usually used for infrastructure construction in seismic regions. In this study, a lever-type lead viscoelastic node damper (LTLVND), which can capture small rotational displacements of the infrastructure under seismic excitation, is innovatively proposed based on the leverage effect. The characteristics of energy-absorbing capacity of the LTLVND and its mitigation effect on the dynamics of the structure under seismic excitation are studied. Testing and modelling results show that a satisfactory energy dissipation effect can be observed for the innovative lead viscoelastic damper (LTLVND). Finally, a seismic analysis of a concrete frame structure with LTLVNDs is carried out. Pushover analysis and dynamic elastoplastic analysis are included. It is shown that a significant improvement in structural performance under seismic conditions can be achieved with the addition of LTLVNDs at appropriate locations.
{"title":"Seismic Mitigation Effect of Lever-Type Lead Viscoelastic Node Dampers","authors":"Mao Ye, Jin Jiang, Jingya Zhou, Wuliang Zhang, Baotao Huang, Ming Wu","doi":"10.1155/2023/1552150","DOIUrl":"https://doi.org/10.1155/2023/1552150","url":null,"abstract":"Energy dissipation damping technology is usually used for infrastructure construction in seismic regions. In this study, a lever-type lead viscoelastic node damper (LTLVND), which can capture small rotational displacements of the infrastructure under seismic excitation, is innovatively proposed based on the leverage effect. The characteristics of energy-absorbing capacity of the LTLVND and its mitigation effect on the dynamics of the structure under seismic excitation are studied. Testing and modelling results show that a satisfactory energy dissipation effect can be observed for the innovative lead viscoelastic damper (LTLVND). Finally, a seismic analysis of a concrete frame structure with LTLVNDs is carried out. Pushover analysis and dynamic elastoplastic analysis are included. It is shown that a significant improvement in structural performance under seismic conditions can be achieved with the addition of LTLVNDs at appropriate locations.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854843","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}
Analysis of recorded seismic response of an eight-story passively-controlled steel building located in Sendai is reported in this paper. Vibration monitoring system has been instrumented to test the effectiveness of dampers and actual performance of passively-controlled structures under earthquake since it was constructed in 2003. A data-driven stochastic subspace identification methodology with an alternative strategy to remove spurious modes is developed and implemented to the recorded actual earthquake response to extract dynamic properties of the passively-controlled eight-story steel building from the recorded floor acceleration data. Thus, the inherent damping characteristic of the building is identified under various earthquakes. Moreover, the variation of the estimated natural frequencies, mode shapes, and damping ratios for all the earthquake recordings are illustrated. To further investigate serviceability of the passively-controlled steel building during an earthquake, probabilistic model updating is developed to estimate the model parameters and infer the response of the structure based on the identified modes. Besides, seismic performance assessment of the passively-controlled steel building from the estimated dynamic characteristics and model parameters during service period is also discussed.
{"title":"Long-Term Seismic Monitoring of a Passively-Controlled Steel Building on Performance Assessment under Strong Earthquake","authors":"Yunjia Tong, Songtao Xue, Liyu Xie, Hesheng Tang","doi":"10.1155/2023/8091965","DOIUrl":"https://doi.org/10.1155/2023/8091965","url":null,"abstract":"Analysis of recorded seismic response of an eight-story passively-controlled steel building located in Sendai is reported in this paper. Vibration monitoring system has been instrumented to test the effectiveness of dampers and actual performance of passively-controlled structures under earthquake since it was constructed in 2003. A data-driven stochastic subspace identification methodology with an alternative strategy to remove spurious modes is developed and implemented to the recorded actual earthquake response to extract dynamic properties of the passively-controlled eight-story steel building from the recorded floor acceleration data. Thus, the inherent damping characteristic of the building is identified under various earthquakes. Moreover, the variation of the estimated natural frequencies, mode shapes, and damping ratios for all the earthquake recordings are illustrated. To further investigate serviceability of the passively-controlled steel building during an earthquake, probabilistic model updating is developed to estimate the model parameters and infer the response of the structure based on the identified modes. Besides, seismic performance assessment of the passively-controlled steel building from the estimated dynamic characteristics and model parameters during service period is also discussed.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135968186","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}
Flexible high-rise buildings with low damping are prone to excessive vibration under strong wind loads. To explore a light-weight control device having desirable mitigation effects on responses and sound robustness against deviations in tuning parameters, the performance of two novel inerter-integrated nonlinear energy sinks (NESIs), i.e., asymmetric nonlinear energy sink inerter (Asym NESI) and cubic NESI, on wind-induced vibration control of super high-rise buildings is assessed in the present work. Based on the wind loads obtained from wind tunnel tests, a super high-rise building with a 300 m height is taken as the host structure in the numerical case study. The results show that Asym NESI can achieve reduction ratios of 38.5% and 11.3% on extreme acceleration and displacement, respectively, while the sensitivity indices of Asym NESI on displacement and acceleration control are only 70.5% and 62.5% of those of tuned mass damper inerter (TMDI) having identical mitigation effects. Although the sensitivity indices of cubic NESI are only 5.5% and 29.8% of those of TMDI, the moderate mitigation effects and large nonlinear stiffness ratio may prohibit its practical implementation. Overall, Asym NESI could be an alternative to TMDI due to the same mitigation effects but better robustness against possible detuning.
{"title":"Asymmetric and Cubic Nonlinear Energy Sink Inerters for Mitigating Wind-Induced Responses of High-Rise Buildings","authors":"Qinhua Wang, Huaxiao Wu, Haoshuai Qiao, Xianfeng Yu, Peng Huang","doi":"10.1155/2023/1150525","DOIUrl":"https://doi.org/10.1155/2023/1150525","url":null,"abstract":"Flexible high-rise buildings with low damping are prone to excessive vibration under strong wind loads. To explore a light-weight control device having desirable mitigation effects on responses and sound robustness against deviations in tuning parameters, the performance of two novel inerter-integrated nonlinear energy sinks (NESIs), i.e., asymmetric nonlinear energy sink inerter (Asym NESI) and cubic NESI, on wind-induced vibration control of super high-rise buildings is assessed in the present work. Based on the wind loads obtained from wind tunnel tests, a super high-rise building with a 300 m height is taken as the host structure in the numerical case study. The results show that Asym NESI can achieve reduction ratios of 38.5% and 11.3% on extreme acceleration and displacement, respectively, while the sensitivity indices of Asym NESI on displacement and acceleration control are only 70.5% and 62.5% of those of tuned mass damper inerter (TMDI) having identical mitigation effects. Although the sensitivity indices of cubic NESI are only 5.5% and 29.8% of those of TMDI, the moderate mitigation effects and large nonlinear stiffness ratio may prohibit its practical implementation. Overall, Asym NESI could be an alternative to TMDI due to the same mitigation effects but better robustness against possible detuning.","PeriodicalId":48981,"journal":{"name":"Structural Control & Health Monitoring","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136064089","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}
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