Gebrail Bekdaş, Ayla Ocak, Sinan Melih Nigdeli, Yusuf Cengiz Toklu
Tensegrity systems are construction system that offers solutions for lighter designs compared with a standard truss system consisting of tension and compression elements. Due to their structure, they are recommended in the design of space structures due to the use of lighter and easy-to-assemble structural elements such as cables, ropes, and similar to provide the desired durability. In this study, energy minimization was carried out to solve the structural element displacements. It is expected to reduce the total potential energy of the system with minimization. By minimizing the total potential energy of the tensegrity system models, the displacement of each building element is found for the equilibrium condition. Tensegrity models were analyzed by minimizing energy via the adaptive harmony search (AHS) algorithm. In this research, two distinct tensegrity structure specimens were employed. One comprised a cantilever beam, while the other adopted a cyclic model, forming eight equal octagons from eight nodes at both the base and the top. Additionally, an examination was conducted on a two-layer iteration of the cyclic model. The method is robust for both space and planar tensegrity structures, allowing the determination of deformed shapes under various loads without design assumptions. The TPO/MA method demonstrates superiority in handling nonlinear and barely stable systems, as evidenced by examples illustrating its efficacy in maintaining structural form under increasing loads and challenging conditions.
{"title":"A metaheuristic-based method for analysis of tensegrity structures","authors":"Gebrail Bekdaş, Ayla Ocak, Sinan Melih Nigdeli, Yusuf Cengiz Toklu","doi":"10.1002/tal.2091","DOIUrl":"https://doi.org/10.1002/tal.2091","url":null,"abstract":"Tensegrity systems are construction system that offers solutions for lighter designs compared with a standard truss system consisting of tension and compression elements. Due to their structure, they are recommended in the design of space structures due to the use of lighter and easy-to-assemble structural elements such as cables, ropes, and similar to provide the desired durability. In this study, energy minimization was carried out to solve the structural element displacements. It is expected to reduce the total potential energy of the system with minimization. By minimizing the total potential energy of the tensegrity system models, the displacement of each building element is found for the equilibrium condition. Tensegrity models were analyzed by minimizing energy via the adaptive harmony search (AHS) algorithm. In this research, two distinct tensegrity structure specimens were employed. One comprised a cantilever beam, while the other adopted a cyclic model, forming eight equal octagons from eight nodes at both the base and the top. Additionally, an examination was conducted on a two-layer iteration of the cyclic model. The method is robust for both space and planar tensegrity structures, allowing the determination of deformed shapes under various loads without design assumptions. The TPO/MA method demonstrates superiority in handling nonlinear and barely stable systems, as evidenced by examples illustrating its efficacy in maintaining structural form under increasing loads and challenging conditions.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139561327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The application of the outrigger technology effectively improves the lateral stiffness of buildings, reduces harmful deformation, enhances the seismic resistance of structures, and contributes to the rapid development of high-rise buildings. To improve the response speed and energy dissipation of a viscous damping outrigger under seismic excitation, a viscous damping outrigger with an amplifier was proposed, and its effectiveness was verified by combining it with the seismic design of a 149.2 m high-rise building in an 8.5-degree intensity area. To determine the additional damping ratio of the building structure, investigations were carried out using both the code method and energy ratio method to evaluate the contribution of the damping outrigger. The damped outrigger equivalent stiffness determination method was studied, and the simplified engineering calculation method was compared against the refined finite element analysis results for engineering design purposes. The displacement amplification technique incorporated into the viscously damped outrigger can enhance the damper response speed, and increase the energy dissipation of the damped outrigger system. The application of an enlarged damped outrigger in engineering can result in an additional damping ratio of approximately 1% while simplifying the calculation method based on the additional damping and equivalent damper cut-line stiffness, which can be useful in engineering design.
{"title":"Application of amplified damped outrigger in seismic design of high-rise buildings","authors":"Hongjing Xue, Zibin Zhao, Pei Li, Weinong Shu, Yu Guan, Dongdong He, Dong Wei, Jincheng Song","doi":"10.1002/tal.2077","DOIUrl":"https://doi.org/10.1002/tal.2077","url":null,"abstract":"The application of the outrigger technology effectively improves the lateral stiffness of buildings, reduces harmful deformation, enhances the seismic resistance of structures, and contributes to the rapid development of high-rise buildings. To improve the response speed and energy dissipation of a viscous damping outrigger under seismic excitation, a viscous damping outrigger with an amplifier was proposed, and its effectiveness was verified by combining it with the seismic design of a 149.2 m high-rise building in an 8.5-degree intensity area. To determine the additional damping ratio of the building structure, investigations were carried out using both the code method and energy ratio method to evaluate the contribution of the damping outrigger. The damped outrigger equivalent stiffness determination method was studied, and the simplified engineering calculation method was compared against the refined finite element analysis results for engineering design purposes. The displacement amplification technique incorporated into the viscously damped outrigger can enhance the damper response speed, and increase the energy dissipation of the damped outrigger system. The application of an enlarged damped outrigger in engineering can result in an additional damping ratio of approximately 1% while simplifying the calculation method based on the additional damping and equivalent damper cut-line stiffness, which can be useful in engineering design.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139497246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper summarizes the literature available on the behavior of concrete-filled steel tubular (CFST) columns to evaluate the effect of geometrical properties such as shape of cross-section, diameter-to-thickness ratio, and length-to-diameter ratio of CFST columns under axial loading. Then, the impact of different material composition for core concrete and encasing material is concluded for columns under axial loading. The performance of CFST is evaluated in terms of failure modes, ductility, stiffness, and axial compressive strength. For encasing tube, carbon steel, stainless steel, and aluminum are studied while for core, various concretes such as Normal (NSC) and high strength concrete (HSC), light weight concrete (LWC), recycled aggregate concrete (RAC), expansive concrete (EC), rubber crumb concrete(RuCC), and steel slag concrete (SSC) are covered for review in this paper. Material limitations as provided by various codes for design of composite structures is also mentioned for both tube and core concrete. Failure modes of concrete-filled tubular(CFT) columns are most affected by geometric properties columns while materials used for concrete and encasing tube do not cause much difference. Though, ductility, axial compressive strength, and stiffness are affected by both geometric and material properties.
{"title":"A review on the performance of concrete filled tubular columns under axial compression: Emphasis on geometrical parameters and various concrete infills and encasings","authors":"Isha Rohilla, Surinder Gupta","doi":"10.1002/tal.2088","DOIUrl":"https://doi.org/10.1002/tal.2088","url":null,"abstract":"This paper summarizes the literature available on the behavior of concrete-filled steel tubular (CFST) columns to evaluate the effect of geometrical properties such as shape of cross-section, diameter-to-thickness ratio, and length-to-diameter ratio of CFST columns under axial loading. Then, the impact of different material composition for core concrete and encasing material is concluded for columns under axial loading. The performance of CFST is evaluated in terms of failure modes, ductility, stiffness, and axial compressive strength. For encasing tube, carbon steel, stainless steel, and aluminum are studied while for core, various concretes such as Normal (NSC) and high strength concrete (HSC), light weight concrete (LWC), recycled aggregate concrete (RAC), expansive concrete (EC), rubber crumb concrete(R<sub>u</sub>CC), and steel slag concrete (SSC) are covered for review in this paper. Material limitations as provided by various codes for design of composite structures is also mentioned for both tube and core concrete. Failure modes of concrete-filled tubular(CFT) columns are most affected by geometric properties columns while materials used for concrete and encasing tube do not cause much difference. Though, ductility, axial compressive strength, and stiffness are affected by both geometric and material properties.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Outriggers are internal structural systems used to enhance the stiffness and strength of high-rise structures. This research investigates the efficacy of a hybrid outrigger system (HOS) which consists of one conventional and one virtual outrigger at two distinct floor levels in high-rise RCC buildings. A non-dimensional quantity, ϒ, defined as the relative stiffness ratio between the core and the diaphragm is used to describe variations in the stiffness of the building's core, stiffness of floor diaphragm, breadth, and height of the structure, in the behavioral analysis of the HOS. To investigate the efficacy and optimum locations of the hybrid outriggers, static and dynamic analysis are carried out on models with four-story heights of 140, 210, 280, and 350 m under static wind loading, uniform wind loading, equivalent static earthquake loading, and dynamic earthquake loading. Results are assessed based on the responses from roof displacement (Disptop), base bending moment, roof acceleration (Acctop), fundamental period, and absolute maximum inter-story drift ratio (ISDabs.max). Based on the minimum responses of the aforementioned dependent parameters under wind and earthquake excitations, the corresponding optimum locations of hybrid outriggers are investigated. To investigate the impact of the slab on the functionality of the HOS, the behavior of shell stress variation in the tension and compression side of the slab at the outrigger floor level and the force transmission through the column at the outrigger level is analyzed. Also, the optimum location of the hybrid outriggers based on the ideal performance index (IdealPI) is investigated. IdealPI is defined as a parameter that considers the combined response of Disptop, Acctop, and ISDabs.max and the criteria required for the structure under wind and seismic loads. From the behavioral analysis results, it is found that an increase in the stiffness of the slab showed an improved performance of the HOS compared to an increase in the stiffness of the core, and HOS performance can be maximized by increasing both thickness of the slab and outrigger arm length. The findings of the optimum location analysis could serve as a guide for structural engineers when selecting suitable positions for hybrid outriggers in high-rise structures.
支腿是一种内部结构系统，用于增强高层建筑结构的刚度和强度。本研究探讨了混合支腿系统（HOS）的功效，该系统由一个传统支腿和一个虚拟支腿组成，分别位于高层 RCC 建筑的两个不同楼层。在 HOS 的行为分析中，使用了一个定义为核心筒和横隔墙之间相对刚度比的非尺寸量 ϒ，来描述建筑物核心筒刚度、楼层横隔墙刚度、宽度和结构高度的变化。为了研究混合支腿的功效和最佳位置，在静态风荷载、均匀风荷载、等效静态地震荷载和动态地震荷载下，对高度分别为 140 米、210 米、280 米和 350 米的四层模型进行了静态和动态分析。评估结果基于屋顶位移（Disptop）、基础弯矩、屋顶加速度（Acctop）、基本周期和绝对最大层间漂移比（ISDabs.max）的响应。根据上述因变参数在风和地震激励下的最小响应，研究了混合支腿的相应最佳位置。为了研究楼板对 HOS 功能的影响，分析了支腿层楼板拉伸侧和压缩侧的壳体应力变化行为，以及支腿层通过柱子的力传递行为。此外，还研究了基于理想性能指数（IdealPI）的混合支腿最佳位置。IdealPI 被定义为一个参数，它考虑了 Disptop、Acctop 和 ISDabs.max 的综合响应，以及结构在风荷载和地震荷载下所需的标准。从行为分析结果中可以发现，与增加核心筒的刚度相比，增加楼板的刚度可以改善 HOS 的性能，而且通过增加楼板厚度和支腿臂长可以最大限度地提高 HOS 的性能。最佳位置分析的结果可为结构工程师在高层建筑中选择混合支腿的合适位置提供指导。
{"title":"Influence of slab structure on the behavioral analysis of hybrid outrigger system","authors":"Neethu Elizabeth John, Kiran Kamath","doi":"10.1002/tal.2080","DOIUrl":"https://doi.org/10.1002/tal.2080","url":null,"abstract":"Outriggers are internal structural systems used to enhance the stiffness and strength of high-rise structures. This research investigates the efficacy of a hybrid outrigger system (HOS) which consists of one conventional and one virtual outrigger at two distinct floor levels in high-rise RCC buildings. A non-dimensional quantity, ϒ, defined as the relative stiffness ratio between the core and the diaphragm is used to describe variations in the stiffness of the building's core, stiffness of floor diaphragm, breadth, and height of the structure, in the behavioral analysis of the HOS. To investigate the efficacy and optimum locations of the hybrid outriggers, static and dynamic analysis are carried out on models with four-story heights of 140, 210, 280, and 350 m under static wind loading, uniform wind loading, equivalent static earthquake loading, and dynamic earthquake loading. Results are assessed based on the responses from roof displacement (Disp<sub>top</sub>), base bending moment, roof acceleration (Acc<sub>top</sub>), fundamental period, and absolute maximum inter-story drift ratio (ISD<sub>abs.max</sub>). Based on the minimum responses of the aforementioned dependent parameters under wind and earthquake excitations, the corresponding optimum locations of hybrid outriggers are investigated. To investigate the impact of the slab on the functionality of the HOS, the behavior of shell stress variation in the tension and compression side of the slab at the outrigger floor level and the force transmission through the column at the outrigger level is analyzed. Also, the optimum location of the hybrid outriggers based on the ideal performance index (Ideal<sub>PI</sub>) is investigated. Ideal<sub>PI</sub> is defined as a parameter that considers the combined response of Disp<sub>top</sub>, Acc<sub>top</sub>, and ISD<sub>abs.max</sub> and the criteria required for the structure under wind and seismic loads. From the behavioral analysis results, it is found that an increase in the stiffness of the slab showed an improved performance of the HOS compared to an increase in the stiffness of the core, and HOS performance can be maximized by increasing both thickness of the slab and outrigger arm length. The findings of the optimum location analysis could serve as a guide for structural engineers when selecting suitable positions for hybrid outriggers in high-rise structures.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139056197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanical characteristics of the setback super-tall structure are complex, and the design is difficult. In the actual analysis and design process, the relevant influencing factors should be fully considered. In this paper, the fine construction simulation analysis of the super-tall structure is carried out. Based on the shrinkage test of concrete members, the CEB-FIP 90 shrinkage model is modified in terms of the parameters of cross-section shape and size. The modified model is used to calculate the shrinkage strain of concrete, and the influence of uneven settlement of foundation and seasonal temperature on the structure is considered in the construction simulation analysis. The influence proportion of each non-load effect on the horizontal displacement, vertical displacement, and internal force of key components is obtained. The refined construction analysis results are compared with the field monitoring data, and the data are in good agreement.
{"title":"Study on the influence of non-load effects during the whole process of construction of setback super-tall structures","authors":"Jun Liu, Bohan Song, Guilong Wu, Xiaoqun Luo, Qilin Zhang, Guijing Yu","doi":"10.1002/tal.2090","DOIUrl":"https://doi.org/10.1002/tal.2090","url":null,"abstract":"The mechanical characteristics of the setback super-tall structure are complex, and the design is difficult. In the actual analysis and design process, the relevant influencing factors should be fully considered. In this paper, the fine construction simulation analysis of the super-tall structure is carried out. Based on the shrinkage test of concrete members, the CEB-FIP 90 shrinkage model is modified in terms of the parameters of cross-section shape and size. The modified model is used to calculate the shrinkage strain of concrete, and the influence of uneven settlement of foundation and seasonal temperature on the structure is considered in the construction simulation analysis. The influence proportion of each non-load effect on the horizontal displacement, vertical displacement, and internal force of key components is obtained. The refined construction analysis results are compared with the field monitoring data, and the data are in good agreement.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138824821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yati Aggarwal, Mahipal Kulariya, Sandip Kumar Saha
The present study investigates the effect of earthquake sequences on the response of reinforced concrete hilly buildings having typical configurations, that is, stepback and split-foundation, with three different story ratios. A set of 30 as-recorded mainshock-aftershock sequence of earthquake ground motions is considered for this study. Mainshock acceleration time histories are scaled at two distinct intensity levels to obtain the mainshock-damaged building. These mainshock-damaged hilly buildings are then subjected to aftershocks. A comparative study is performed for various response quantities, such as peak interstory drift ratio, peak floor acceleration, and peak roof displacement of undamaged and mainshock-damaged buildings under aftershocks. Further, fragility analysis is carried out to study the effect of aftershocks on undamaged and mainshock-damaged hilly buildings. Subsequently, component-wise seismic loss estimation due to damage in the non-structural and structural components is performed. It is concluded from the study that the building components that contribute maximum to the expected repair cost ratio vary with respect to the intensity of the aftershocks. Also, the estimated seismic loss is higher in mainshock-damaged split-foundation buildings in comparison to stepback buildings.
{"title":"Seismic performance evaluation of reinforced concrete hilly buildings under sequence of earthquakes","authors":"Yati Aggarwal, Mahipal Kulariya, Sandip Kumar Saha","doi":"10.1002/tal.2086","DOIUrl":"https://doi.org/10.1002/tal.2086","url":null,"abstract":"The present study investigates the effect of earthquake sequences on the response of reinforced concrete hilly buildings having typical configurations, that is, stepback and split-foundation, with three different story ratios. A set of 30 as-recorded mainshock-aftershock sequence of earthquake ground motions is considered for this study. Mainshock acceleration time histories are scaled at two distinct intensity levels to obtain the mainshock-damaged building. These mainshock-damaged hilly buildings are then subjected to aftershocks. A comparative study is performed for various response quantities, such as peak interstory drift ratio, peak floor acceleration, and peak roof displacement of undamaged and mainshock-damaged buildings under aftershocks. Further, fragility analysis is carried out to study the effect of aftershocks on undamaged and mainshock-damaged hilly buildings. Subsequently, component-wise seismic loss estimation due to damage in the non-structural and structural components is performed. It is concluded from the study that the building components that contribute maximum to the expected repair cost ratio vary with respect to the intensity of the aftershocks. Also, the estimated seismic loss is higher in mainshock-damaged split-foundation buildings in comparison to stepback buildings.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138824611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coal-fired thermal power plants play important roles in daily life but are vulnerable to earthquakes. This paper presents a novel cable-damper stopper with linear damping and carries out a series of shaking table tests to evaluate its performance on a 1/25-scaled coal-fired thermal power plant. The stopper consists of a cable, a linear viscous damper and a steel block attached to the boiler. The seismic responses of the structure equipped with different sets of cable-damper stoppers which are of different damping coefficients and diameters of cables were studied and evaluated, where three seismic ground motions with two intensities were selected as input motions. The obtained acceleration and displacement responses of the support structure and the boiler reveal that the stopper cable effectively restrains the relative displacement between the boiler and the support structure. Furthermore, it can be found that the damping affects the seismic protection performance of the stopper depending on the intensity of the boiler vibration. In the paper, the working mechanism of the stopper is also analyzed based on the test data. It turns out that the stopper is more effective when it works under severe earthquakes.
{"title":"Shaking table test of the shock absorbing performance of a new cable-damper stopper for coal-fired thermal power plants","authors":"Yuheng Jiang, Liping Duan, Feng Yue, Jincheng Zhao","doi":"10.1002/tal.2083","DOIUrl":"https://doi.org/10.1002/tal.2083","url":null,"abstract":"Coal-fired thermal power plants play important roles in daily life but are vulnerable to earthquakes. This paper presents a novel cable-damper stopper with linear damping and carries out a series of shaking table tests to evaluate its performance on a 1/25-scaled coal-fired thermal power plant. The stopper consists of a cable, a linear viscous damper and a steel block attached to the boiler. The seismic responses of the structure equipped with different sets of cable-damper stoppers which are of different damping coefficients and diameters of cables were studied and evaluated, where three seismic ground motions with two intensities were selected as input motions. The obtained acceleration and displacement responses of the support structure and the boiler reveal that the stopper cable effectively restrains the relative displacement between the boiler and the support structure. Furthermore, it can be found that the damping affects the seismic protection performance of the stopper depending on the intensity of the boiler vibration. In the paper, the working mechanism of the stopper is also analyzed based on the test data. It turns out that the stopper is more effective when it works under severe earthquakes.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138824598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chuanguo Jia, Yutao Li, Hongchen Su, Min Gan, Longchang Chen, Weinan Guo
In seismic response analysis of seismically isolated structures (SISs), the nonlinearity is concentrated in the isolation layer while the upper structure behaves linearly, making SISs locally nonlinear systems. This paper proposed a novel seismic analysis method based on equivalent linearization (EL) and iterative solution for SISs. In this method, the equilibrium equations of an SIS are expressed by the second-order ordinary differential equations of the structural system as well as the hysteretic force of seismic isolation bearings (SIBs). Based on EL theory, the linearized equilibrium equations of the overall system were reconstructed in which the EL parameters are derived theoretically. The inter-history iteration (IHI) method was proposed to solve the linearized equation system and calculate the EL parameters in sequence iteratively for seismic response analysis of SISs, thus reducing computational cost without excessive loss of accuracy. In addition, the secondary development of the proposed method was programmed in ABAQUS for ease of engineering applications. Finally, the convergence and accuracy of the method were investigated through numerical simulation of an SIS case study. As the numerical investigation indicates, the proposed method considers the coupling between structural response and the EL parameters, achieving a high convergence rate and satisfactory solution accuracy. The ABAQUS secondary development program utilizes the powerful pre-processor, post-processor, and solvers of ABAQUS, making the IHI method more appropriate for engineering applications.
在隔震结构（SIS）的地震反应分析中，非线性集中在隔震层，而上部结构表现为线性，这使得 SIS 成为局部非线性系统。本文提出了一种基于等效线性化（EL）和迭代求解的新型 SIS 地震分析方法。在该方法中，SIS 的平衡方程由结构系统的二阶常微分方程以及隔震支座（SIB）的滞后力来表示。根据 EL 理论，重建了整个系统的线性化平衡方程，其中 EL 参数是通过理论推导得出的。提出了历史间迭代法（IHI）来求解线性化方程组，并依次迭代计算 EL 参数，用于 SIS 的地震响应分析，从而在不损失过多精度的情况下降低了计算成本。此外，为了便于工程应用，还在 ABAQUS 中对所提方法进行了二次开发编程。最后，通过对一个 SIS 案例的数值模拟，研究了该方法的收敛性和准确性。数值研究结果表明，所提方法考虑了结构响应与 EL 参数之间的耦合，收敛率高，求解精度令人满意。ABAQUS 二次开发程序利用 ABAQUS 强大的前处理器、后处理器和求解器，使 IHI 方法更适合工程应用。
{"title":"The inter-history iteration method for seismic response analysis of seismically isolated structures and its secondary development based on ABAQUS","authors":"Chuanguo Jia, Yutao Li, Hongchen Su, Min Gan, Longchang Chen, Weinan Guo","doi":"10.1002/tal.2078","DOIUrl":"https://doi.org/10.1002/tal.2078","url":null,"abstract":"In seismic response analysis of seismically isolated structures (SISs), the nonlinearity is concentrated in the isolation layer while the upper structure behaves linearly, making SISs locally nonlinear systems. This paper proposed a novel seismic analysis method based on equivalent linearization (EL) and iterative solution for SISs. In this method, the equilibrium equations of an SIS are expressed by the second-order ordinary differential equations of the structural system as well as the hysteretic force of seismic isolation bearings (SIBs). Based on EL theory, the linearized equilibrium equations of the overall system were reconstructed in which the EL parameters are derived theoretically. The inter-history iteration (IHI) method was proposed to solve the linearized equation system and calculate the EL parameters in sequence iteratively for seismic response analysis of SISs, thus reducing computational cost without excessive loss of accuracy. In addition, the secondary development of the proposed method was programmed in ABAQUS for ease of engineering applications. Finally, the convergence and accuracy of the method were investigated through numerical simulation of an SIS case study. As the numerical investigation indicates, the proposed method considers the coupling between structural response and the EL parameters, achieving a high convergence rate and satisfactory solution accuracy. The ABAQUS secondary development program utilizes the powerful pre-processor, post-processor, and solvers of ABAQUS, making the IHI method more appropriate for engineering applications.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138824886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lin Chen, Ping Tan, Xiaofeng Zhao, Yafei Xu, Fulin Zhou
Current analytical models for outrigger structures in super high-rise buildings tend to oversimplify by not considering the stiffness of individual floors. This paper introduces a more refined calculation model, based on the substructure method, which takes floor stiffness into account. To verify our proposed approach, we derived a mathematical algorithm and developed a finite element model using ANSYS. When compared to traditional methods that only account for outrigger stiffness, our model, which incorporates both outrigger and floor stiffness, provides improved accuracy in calculating vertex displacement. It also suggests an upward shift in the optimal position for the outrigger and bolsters the overall building's lateral stiffness. To further our analysis, we introduced an equivalent stiffness calculation formula, using the Bayesian parameter estimation method. When applied to dynamic analysis, this formula aligns closely with the results from the finite element simulations. Furthermore, the suggested algorithm for determining the best position for the outrigger is consistent with theoretical calculations. By considering the contribution of regular floors to the overall structure, we found that the fitted equivalent core tube stiffness offers a reliable reflection of structural stiffness. Lastly, when this equivalent stiffness was applied to a dynamic analysis based on Rayleigh's energy method, there was a noticeable reduction in computational effort. This yields not only more efficient calculations but also precise results, rendering it particularly valuable during the initial design phases of high-rise buildings.
{"title":"Improved analytic method for outrigger structures considering floor stiffness","authors":"Lin Chen, Ping Tan, Xiaofeng Zhao, Yafei Xu, Fulin Zhou","doi":"10.1002/tal.2076","DOIUrl":"https://doi.org/10.1002/tal.2076","url":null,"abstract":"Current analytical models for outrigger structures in super high-rise buildings tend to oversimplify by not considering the stiffness of individual floors. This paper introduces a more refined calculation model, based on the substructure method, which takes floor stiffness into account. To verify our proposed approach, we derived a mathematical algorithm and developed a finite element model using ANSYS. When compared to traditional methods that only account for outrigger stiffness, our model, which incorporates both outrigger and floor stiffness, provides improved accuracy in calculating vertex displacement. It also suggests an upward shift in the optimal position for the outrigger and bolsters the overall building's lateral stiffness. To further our analysis, we introduced an equivalent stiffness calculation formula, using the Bayesian parameter estimation method. When applied to dynamic analysis, this formula aligns closely with the results from the finite element simulations. Furthermore, the suggested algorithm for determining the best position for the outrigger is consistent with theoretical calculations. By considering the contribution of regular floors to the overall structure, we found that the fitted equivalent core tube stiffness offers a reliable reflection of structural stiffness. Lastly, when this equivalent stiffness was applied to a dynamic analysis based on Rayleigh's energy method, there was a noticeable reduction in computational effort. This yields not only more efficient calculations but also precise results, rendering it particularly valuable during the initial design phases of high-rise buildings.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138716119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reinforced concrete (RC) shear walls play an important role as the seismic resisting system in tall buildings. Yet, assessing the seismic damage of real-world shear walls remains a challenging task. In this study, a damage index that relies on the vibration data measured by the sensors embedded in the structure is proposed to evaluate the damage condition of shear walls. The damage index is formed by the linear combination of two normalized terms, which, respectively, characterize the peak and the cumulative damages of the shear walls with little knowledge of real-life structural hysteresis. The damage tracking and evaluation based on the substructure level and the story level are discussed. The damage indices evaluated using the hysteretic loops made by the shear and bending information of the shear wall are further compared. The feasibility of the proposed damage index is examined using a numerically simulated 12-story coupled shear wall structure. It is then applied to analyze the experiments regarding the damage condition of RC shear walls under earthquakes. Results show that the proposed damage index can track the damage states of RC shear walls under seismic excitations. Analysis suggests that the proposed damage index could trace and distinguish the progression of shear and flexural damages, which potentially supports the post-earthquake structural safety management.
{"title":"Damage tracking and hysteresis-based evaluation of seismic-excited RC shear wall using monitoring data","authors":"Jiazeng Shan, Luji Wang, Cheng Ning Loong, Hanqing Zhang, Peican Huang","doi":"10.1002/tal.2087","DOIUrl":"https://doi.org/10.1002/tal.2087","url":null,"abstract":"Reinforced concrete (RC) shear walls play an important role as the seismic resisting system in tall buildings. Yet, assessing the seismic damage of real-world shear walls remains a challenging task. In this study, a damage index that relies on the vibration data measured by the sensors embedded in the structure is proposed to evaluate the damage condition of shear walls. The damage index is formed by the linear combination of two normalized terms, which, respectively, characterize the peak and the cumulative damages of the shear walls with little knowledge of real-life structural hysteresis. The damage tracking and evaluation based on the substructure level and the story level are discussed. The damage indices evaluated using the hysteretic loops made by the shear and bending information of the shear wall are further compared. The feasibility of the proposed damage index is examined using a numerically simulated 12-story coupled shear wall structure. It is then applied to analyze the experiments regarding the damage condition of RC shear walls under earthquakes. Results show that the proposed damage index can track the damage states of RC shear walls under seismic excitations. Analysis suggests that the proposed damage index could trace and distinguish the progression of shear and flexural damages, which potentially supports the post-earthquake structural safety management.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138716039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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