Pub Date : 2024-11-17DOI: 10.1016/j.jcsr.2024.109153
Zi-Qin Jiang , Zi-Yao Niu , Xiao-Feng Yang , Zhong-Shuai Yang , Taichiro Okazaki
A self-centering prestressed beam-column connection (SCPBCC) with weakened flange cover plate (FCP) is proposed to achieve self-centering features and post-earthquake recoverability at reasonable cost. The self-centering and energy dissipation capacity of SCPBCC are controlled respectively by the prestressed cable and FCP, and the bearing capacity of SCPBCC is controlled by adjusting the bearing ratio of the cable and FCP. Five SCPBCC specimens were subjected to large and small-amplitude, cyclic-loading tests. The test results demonstrated that the new SCPBCC can meet requirements of stiffness and strength, achieve excellent self-centering features, survive multiple aftershocks and allows for replacement. The connection can supply ample energy dissipation through cyclic yielding of the FCPs. Reasonable variable section and limited prestress can protect beams and the column from plastic deformation. The proposed design methodology ensures good bearing and self-resetting capacity for SCPBCCs.
{"title":"Cyclic behavior of steel self-centering prestressed beam-column connection with weakened FCP","authors":"Zi-Qin Jiang , Zi-Yao Niu , Xiao-Feng Yang , Zhong-Shuai Yang , Taichiro Okazaki","doi":"10.1016/j.jcsr.2024.109153","DOIUrl":"10.1016/j.jcsr.2024.109153","url":null,"abstract":"<div><div>A self-centering prestressed beam-column connection (SCPBCC) with weakened flange cover plate (FCP) is proposed to achieve self-centering features and post-earthquake recoverability at reasonable cost. The self-centering and energy dissipation capacity of SCPBCC are controlled respectively by the prestressed cable and FCP, and the bearing capacity of SCPBCC is controlled by adjusting the bearing ratio of the cable and FCP. Five SCPBCC specimens were subjected to large and small-amplitude, cyclic-loading tests. The test results demonstrated that the new SCPBCC can meet requirements of stiffness and strength, achieve excellent self-centering features, survive multiple aftershocks and allows for replacement. The connection can supply ample energy dissipation through cyclic yielding of the FCPs. Reasonable variable section and limited prestress can protect beams and the column from plastic deformation. The proposed design methodology ensures good bearing and self-resetting capacity for SCPBCCs.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109153"},"PeriodicalIF":4.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652287","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}
Pub Date : 2024-11-16DOI: 10.1016/j.jcsr.2024.109143
Brendan Richards , Kamran Tayyebi , Min Sun , Kyle Tousignant
An evaluation of North American and European design provisions for rectangular hollow section (RHS) flexural members with slender elements is performed. Seventy-three non-linear finite element models, covering practical ranges of width-to-thickness, height-to-thickness, and aspect ratio are developed, validated, and analyzed. The results demonstrate that current Class 3 or non-compact limit(s) in CSA S16, AISC 360, and EN 1990 are accurate; however, the effective width methods used in the current nominal strength expressions are inconsistent across different RHS orientations, and conservative (up to 11 %). To address this, a new effective stress approach using gross-section properties was explored. The new approach is shown to increase (up to 9 %) the accuracy and precision of nominal strength predictions when compared to the current approach(es), for all orientations, and still meet/exceed target reliability indices based on an approximate first-order reliability method analysis.
{"title":"An effective stress approach for the design of rectangular hollow section flexural members with slender elements","authors":"Brendan Richards , Kamran Tayyebi , Min Sun , Kyle Tousignant","doi":"10.1016/j.jcsr.2024.109143","DOIUrl":"10.1016/j.jcsr.2024.109143","url":null,"abstract":"<div><div>An evaluation of North American and European design provisions for rectangular hollow section (RHS) flexural members with slender elements is performed. Seventy-three non-linear finite element models, covering practical ranges of width-to-thickness, height-to-thickness, and aspect ratio are developed, validated, and analyzed. The results demonstrate that current Class 3 or non-compact limit(s) in CSA S16, AISC 360, and EN 1990 are accurate; however, the effective width methods used in the current nominal strength expressions are inconsistent across different RHS orientations, and conservative (up to 11 %). To address this, a new effective stress approach using gross-section properties was explored. The new approach is shown to increase (up to 9 %) the accuracy and precision of nominal strength predictions when compared to the current approach(es), for all orientations, and still meet/exceed target reliability indices based on an approximate first-order reliability method analysis.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109143"},"PeriodicalIF":4.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652284","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}
Pub Date : 2024-11-16DOI: 10.1016/j.jcsr.2024.109152
Mingming Yu , Shuailing Li , Xu Xie
Machine learning (ML) has gradually developed into an effective method for fatigue life prediction. However, training an accurate and robust ML model is challenging when the data points resulting from expensive tests are scarce. This study proposed and validated of using synthetic ultra-low cycle fatigue (ULCF) life data generated by tabular generative adversarial network (GAN) as input for ML models. The ULCF life prediction using synthetic data was conducted for structural steels through artificial neural network (ANN) and multi-fidelity deep neural network (MFDNN). The results demonstrated that the ANN_Syn model trained with original experimental data plus synthetic data possessed higher mean value and lower standard deviation of R2 in ULCF life prediction, compared to the ANN model trained with original experimental data only. The pioneeringly constructed MFDNN model with synthetic data by tabular GAN can generally have good predictive performance. The synthetic data size had more significant influence on the predictive ability of MFDNN model than that of ANN_Syn model. The results of this study will promote the application of ML models on ULCF life prediction of structural steels, thereby greatly reducing the cost of parameters calibration of models for ULCF damage evaluation of steel structures.
机器学习（ML）已逐渐发展成为一种有效的疲劳寿命预测方法。然而，在昂贵的测试所产生的数据点稀缺的情况下，训练一个准确且稳健的 ML 模型具有挑战性。本研究提出并验证了使用表格生成式对抗网络（GAN）生成的合成超低循环疲劳（ULCF）寿命数据作为 ML 模型的输入。通过人工神经网络（ANN）和多保真度深度神经网络（MFDNN）使用合成数据对结构钢进行了超低循环疲劳寿命预测。结果表明，与仅使用原始实验数据训练的 ANN 模型相比，使用原始实验数据和合成数据训练的 ANN_Syn 模型在 ULCF 寿命预测中具有更高的 R2 平均值和更低的标准偏差。通过表格 GAN 利用合成数据率先构建的 MFDNN 模型总体上具有良好的预测性能。与 ANN_Syn 模型相比，合成数据的大小对 MFDNN 模型预测能力的影响更为显著。本研究的结果将促进 ML 模型在钢结构 ULCF 寿命预测中的应用，从而大大降低钢结构 ULCF 损伤评估模型参数标定的成本。
{"title":"Machine learning for ULCF life prediction of structural steels with synthetic data","authors":"Mingming Yu , Shuailing Li , Xu Xie","doi":"10.1016/j.jcsr.2024.109152","DOIUrl":"10.1016/j.jcsr.2024.109152","url":null,"abstract":"<div><div>Machine learning (ML) has gradually developed into an effective method for fatigue life prediction. However, training an accurate and robust ML model is challenging when the data points resulting from expensive tests are scarce. This study proposed and validated of using synthetic ultra-low cycle fatigue (ULCF) life data generated by tabular generative adversarial network (GAN) as input for ML models. The ULCF life prediction using synthetic data was conducted for structural steels through artificial neural network (ANN) and multi-fidelity deep neural network (MFDNN). The results demonstrated that the ANN_Syn model trained with original experimental data plus synthetic data possessed higher mean value and lower standard deviation of <em>R</em><sup>2</sup> in ULCF life prediction, compared to the ANN model trained with original experimental data only. The pioneeringly constructed MFDNN model with synthetic data by tabular GAN can generally have good predictive performance. The synthetic data size had more significant influence on the predictive ability of MFDNN model than that of ANN_Syn model. The results of this study will promote the application of ML models on ULCF life prediction of structural steels, thereby greatly reducing the cost of parameters calibration of models for ULCF damage evaluation of steel structures.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109152"},"PeriodicalIF":4.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652285","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}
Implementing a circular economy in construction is one of the potential approaches to limit the natural resource consumption by the construction industry and construction waste generation after demolition. There exist necessities for constructing buildings with easier demountability and direct reusability. One of the key aspects of reuse is designing with structural connections for demountability after service life, rendering the buildings for reuse. Therefore, this study endeavours to develop a directly reusable interlocking hold-down type column base connection for steel structures through full-scale experimental and theoretical investigations. The new reusable column base connection consists of a connector plate to replace the anchor rods in the traditional exposed column base connections to connect the concrete footing with the steel column and base plate assembly. This paper investigates the structural behaviour of the new reusable column base connection subjected to monotonic lateral loading and determines the effective embedment depth required for the connector to avoid concrete failure. A loading protocol that signifies reuse through repeated loading sequences is adopted for this study. Thus, each specimen is loaded for three repeated reuse cycles. A theoretical method based on the traditional component model concept representing the connection components as a combination of spring assembly is developed to predict the initial elastic stiffness of the connection. This will consequently aid in estimating the lateral displacement occurring for the corresponding design load. The theoretically predicted stiffness values are in good correlation with the experimental results. The design example for stiffness calculation is also provided for industrial practical applicability.
{"title":"Experimental Investigations on Structural Behaviour of Reusable Interlocking Steel column base Connection with Demountability","authors":"Aswin Kumar Rajakala Jeyabalan , Sivaganesh Kanmani Selvaraj , Tak-Ming Chan","doi":"10.1016/j.jcsr.2024.109146","DOIUrl":"10.1016/j.jcsr.2024.109146","url":null,"abstract":"<div><div>Implementing a circular economy in construction is one of the potential approaches to limit the natural resource consumption by the construction industry and construction waste generation after demolition. There exist necessities for constructing buildings with easier demountability and direct reusability. One of the key aspects of reuse is designing with structural connections for demountability after service life, rendering the buildings for reuse. Therefore, this study endeavours to develop a directly reusable interlocking hold-down type column base connection for steel structures through full-scale experimental and theoretical investigations. The new reusable column base connection consists of a connector plate to replace the anchor rods in the traditional exposed column base connections to connect the concrete footing with the steel column and base plate assembly. This paper investigates the structural behaviour of the new reusable column base connection subjected to monotonic lateral loading and determines the effective embedment depth required for the connector to avoid concrete failure. A loading protocol that signifies reuse through repeated loading sequences is adopted for this study. Thus, each specimen is loaded for three repeated reuse cycles. A theoretical method based on the traditional component model concept representing the connection components as a combination of spring assembly is developed to predict the initial elastic stiffness of the connection. This will consequently aid in estimating the lateral displacement occurring for the corresponding design load. The theoretically predicted stiffness values are in good correlation with the experimental results. The design example for stiffness calculation is also provided for industrial practical applicability.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109146"},"PeriodicalIF":4.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652283","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}
Pub Date : 2024-11-16DOI: 10.1016/j.jcsr.2024.109161
Wei Bao , Sheng Long , Dongying Liu , Zhiwei Yu , Jiaopeng Fang , Wenzhe Lin
This study focuses on investigating the seismic performance of semi-rigid steel frames (SSFs) reinforced with wall plates and a novel wall-beam connector (WBC). The aim is to address the inherent limitations of these frames regarding lateral resistance and susceptibility to local instability. To evaluate the effectiveness of the proposed reinforcement, three specimens were subjected to pseudo-static cyclic loading. One specimen represented a standard SSF without wall plates, while the other two specimens were supported by wall plates with WBCs of different thicknesses (3 mm and 5 mm). The comparative analysis of the three specimens revealed significant improvements in seismic performance and energy dissipation capacities resulting from the inclusion of the WBCs. The WBCs facilitated displacement deformation, effectively mitigating structural damage caused by seismic forces. Notably, the introduction of WBCs led to a substantial increase in initial stiffness (45.2 % for WBC1 and 111.3 % for WBC2) and a significant enhancement in ultimate bearing capacity (251.9 % increase for WBC2) compared to the standard SSF. The thickness of the WBCs emerged as a crucial factor in regulating the load-bearing capacity, stiffness, and energy dissipation of the structure. The integration of WBCs ensured stable load-bearing functionality for both the frame and wall plate, effectively utilizing the material properties of each component. This configuration enhanced the lateral stiffness and hysteretic behavior of the structure, facilitating staged and incremental yielding and plastic energy dissipation under varying inter-story drifts.
{"title":"Seismic performance of wall plate supported semi-rigid steel frames with a novel type of wall-beam connector","authors":"Wei Bao , Sheng Long , Dongying Liu , Zhiwei Yu , Jiaopeng Fang , Wenzhe Lin","doi":"10.1016/j.jcsr.2024.109161","DOIUrl":"10.1016/j.jcsr.2024.109161","url":null,"abstract":"<div><div>This study focuses on investigating the seismic performance of semi-rigid steel frames (SSFs) reinforced with wall plates and a novel wall-beam connector (WBC). The aim is to address the inherent limitations of these frames regarding lateral resistance and susceptibility to local instability. To evaluate the effectiveness of the proposed reinforcement, three specimens were subjected to pseudo-static cyclic loading. One specimen represented a standard SSF without wall plates, while the other two specimens were supported by wall plates with WBCs of different thicknesses (3 mm and 5 mm). The comparative analysis of the three specimens revealed significant improvements in seismic performance and energy dissipation capacities resulting from the inclusion of the WBCs. The WBCs facilitated displacement deformation, effectively mitigating structural damage caused by seismic forces. Notably, the introduction of WBCs led to a substantial increase in initial stiffness (45.2 % for WBC1 and 111.3 % for WBC2) and a significant enhancement in ultimate bearing capacity (251.9 % increase for WBC2) compared to the standard SSF. The thickness of the WBCs emerged as a crucial factor in regulating the load-bearing capacity, stiffness, and energy dissipation of the structure. The integration of WBCs ensured stable load-bearing functionality for both the frame and wall plate, effectively utilizing the material properties of each component. This configuration enhanced the lateral stiffness and hysteretic behavior of the structure, facilitating staged and incremental yielding and plastic energy dissipation under varying inter-story drifts.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109161"},"PeriodicalIF":4.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652286","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}
Pub Date : 2024-11-15DOI: 10.1016/j.jcsr.2024.109154
Weiwei Xie , Jian Wang , Yan Rong , Wei Zhang , LuFeng Yang
An efficient and high-precision linear elastic iterative method is proposed for ultimate bearing capacity analysis of rectangular concrete-filled steel tube (CFST) trusses, based on the homogeneous generalized yield function (HGYF). Firstly, a fiber model method is developed for evaluating the bearing capacity of rectangular CFST members under combined compression and bending. The influence of material strength and cross-sectional geometric parameters on HGYF of rectangular CFST members is investigated, and the main influencing factors are determined. Then, a HGYF for rectangular CFST members with wide applicability is formulated, based on which the element bearing ratio is defined and a linear elastic iterative method for ultimate bearing capacity analysis of rectangular CFST trusses is introduced on the basis of the elastic modulus reduction method. Finally, the results of the proposed method are compared with test data, generalized yield function (GYF) based results and the results from the traditional incremental nonlinear finite element method (INFEM). Results indicate that the presented HGYF can accurately predict the ultimate bearing capacity of rectangular CFST members while effectively addressing the limitations of GYF. Meanwhile, the proposed HGYF based method agrees well with the test results with high accuracy and efficiency, and can accurately identify the high and low bearing members of truss structure.
{"title":"HGYF based ultimate bearing capacity analysis of rectangular CFST trusses","authors":"Weiwei Xie , Jian Wang , Yan Rong , Wei Zhang , LuFeng Yang","doi":"10.1016/j.jcsr.2024.109154","DOIUrl":"10.1016/j.jcsr.2024.109154","url":null,"abstract":"<div><div>An efficient and high-precision linear elastic iterative method is proposed for ultimate bearing capacity analysis of rectangular concrete-filled steel tube (CFST) trusses, based on the homogeneous generalized yield function (HGYF). Firstly, a fiber model method is developed for evaluating the bearing capacity of rectangular CFST members under combined compression and bending. The influence of material strength and cross-sectional geometric parameters on HGYF of rectangular CFST members is investigated, and the main influencing factors are determined. Then, a HGYF for rectangular CFST members with wide applicability is formulated, based on which the element bearing ratio is defined and a linear elastic iterative method for ultimate bearing capacity analysis of rectangular CFST trusses is introduced on the basis of the elastic modulus reduction method. Finally, the results of the proposed method are compared with test data, generalized yield function (GYF) based results and the results from the traditional incremental nonlinear finite element method (INFEM). Results indicate that the presented HGYF can accurately predict the ultimate bearing capacity of rectangular CFST members while effectively addressing the limitations of GYF. Meanwhile, the proposed HGYF based method agrees well with the test results with high accuracy and efficiency, and can accurately identify the high and low bearing members of truss structure.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109154"},"PeriodicalIF":4.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652347","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}
Pub Date : 2024-11-15DOI: 10.1016/j.jcsr.2024.109160
Zhenhua Wang , Zhihong Zhang , Zhangli Peng , Xinran Wang , Jiankai Chen , Xinzan Hu
A hybrid cable-truss structure has been previously utilized in the Maracana Stadium. There are two ways to design the initial prestress distribution in the hybrid cable-truss structure, taking into account the functionality of the upper and lower hoop cables. This study proposes a decomposition method for determining the form-finding of circular hybrid cable-truss structures with two different prestress distributions. The hybrid cable-truss structure is decomposed into the inner and outer cable-truss structures. The PBS (partial balance strategy) method is employed to design the prestress and shape of both the inner and outer cable-truss structures with consideration of self-weight. A detailed prestress and shape design analysis of a circular hybrid cable-truss structure with two prestress distributions is conducted, and the precision of the initial prestress design is analyzed. The illustrative example presented herein demonstrates that the proposed method, combined with the PBS method, provides a simple and accurate approach for the form-finding of hybrid cable-truss roof systems subject to self-weight.
{"title":"A decomposition method for form-finding of circular hybrid cable-truss structures considering self-weight","authors":"Zhenhua Wang , Zhihong Zhang , Zhangli Peng , Xinran Wang , Jiankai Chen , Xinzan Hu","doi":"10.1016/j.jcsr.2024.109160","DOIUrl":"10.1016/j.jcsr.2024.109160","url":null,"abstract":"<div><div>A hybrid cable-truss structure has been previously utilized in the Maracana Stadium. There are two ways to design the initial prestress distribution in the hybrid cable-truss structure, taking into account the functionality of the upper and lower hoop cables. This study proposes a decomposition method for determining the form-finding of circular hybrid cable-truss structures with two different prestress distributions. The hybrid cable-truss structure is decomposed into the inner and outer cable-truss structures. The PBS (partial balance strategy) method is employed to design the prestress and shape of both the inner and outer cable-truss structures with consideration of self-weight. A detailed prestress and shape design analysis of a circular hybrid cable-truss structure with two prestress distributions is conducted, and the precision of the initial prestress design is analyzed. The illustrative example presented herein demonstrates that the proposed method, combined with the PBS method, provides a simple and accurate approach for the form-finding of hybrid cable-truss roof systems subject to self-weight.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109160"},"PeriodicalIF":4.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652501","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}
Pub Date : 2024-11-15DOI: 10.1016/j.jcsr.2024.109166
Jun Zou , Jinyu Lu , Na Li , Haichen Zhang , Zhicheng Sha , Zhiyin Xu
The control accuracy and sensitivity of active struts in traditional adaptive beam string structures (ABSS) pose significant challenges to meeting the control requirements in different working states, which will seriously limit its adaptability to various external environments. To address this issue, a double rhombic active strut adaptive beam string structure (DRSABSS) was developed. To analyze the working mechanism of the double rhombic active strut and its feasibility in structural active control, its geometric deformation model was established, and the design formula was derived. The experiments and numerical simulations were conducted on a scaled model of the DRSABSS under different load cases. A control strategy that minimizes displacement considering control accuracy and sensitivity was proposed based on a genetic algorithm (GA). The test and simulation results showed that the initial angle of the double rhombic active strut was a crucial factor in determining its control function, and the accuracy of its design formula was verified. Additionally, the structural responses were significantly reduced after active control, and the double rhombic active struts can improve the structural control accuracy and sensitivity simultaneously, and the flexible switching of control modes under different requirements in real-time can be achieved. The test results were in good agreement with the simulation results. The rhombic amplification mechanism of DRSABSS proposed in this paper provides a new approach to improve the control accuracy and sensitivity of adaptive structures, and it can be applicable to the control requirements under different loads.
{"title":"Control accuracy and sensitivity of a double rhombic-strut adaptive beam string structure","authors":"Jun Zou , Jinyu Lu , Na Li , Haichen Zhang , Zhicheng Sha , Zhiyin Xu","doi":"10.1016/j.jcsr.2024.109166","DOIUrl":"10.1016/j.jcsr.2024.109166","url":null,"abstract":"<div><div>The control accuracy and sensitivity of active struts in traditional adaptive beam string structures (ABSS) pose significant challenges to meeting the control requirements in different working states, which will seriously limit its adaptability to various external environments. To address this issue, a double rhombic active strut adaptive beam string structure (DRSABSS) was developed. To analyze the working mechanism of the double rhombic active strut and its feasibility in structural active control, its geometric deformation model was established, and the design formula was derived. The experiments and numerical simulations were conducted on a scaled model of the DRSABSS under different load cases. A control strategy that minimizes displacement considering control accuracy and sensitivity was proposed based on a genetic algorithm (GA). The test and simulation results showed that the initial angle of the double rhombic active strut was a crucial factor in determining its control function, and the accuracy of its design formula was verified. Additionally, the structural responses were significantly reduced after active control, and the double rhombic active struts can improve the structural control accuracy and sensitivity simultaneously, and the flexible switching of control modes under different requirements in real-time can be achieved. The test results were in good agreement with the simulation results. The rhombic amplification mechanism of DRSABSS proposed in this paper provides a new approach to improve the control accuracy and sensitivity of adaptive structures, and it can be applicable to the control requirements under different loads.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109166"},"PeriodicalIF":4.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652348","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}
Pub Date : 2024-11-15DOI: 10.1016/j.jcsr.2024.109164
Qinglin Jia , Lin Xiao , Heng Liu , Xing Wei , Zhirui Kang
This study reports the results of post-fire axial compressive tests on 87 basalt fiber recycled aggregate concrete (BFRAC) cubes and 25 basalt fiber recycled aggregate concrete filled steel tube (BF-RACFST) short columns. The variables were temperature (20, 300, 500, and 800 °C), recycled aggregate replacement ratio (0, 50, and 100 %), basalt fiber content (0, 4, and 8 kg/m3), and cooling method. The specimens were firstly heated at constant high temperatures. After cooling to room temperature, the axial compression tests were conducted. The findings revealed that recycled aggregate prevented explosive spalling of BFRAC but reduced the post-fire capacity and stiffness of BF-RACFST. Adding basalt fiber increased the compressive strength of BFRAC cubes, decreased BF-RACFST post-fire capacity, and slightly increased the post-fire compressive stiffness of the short columns. After cooling in water, the load and failure capacity of BF-RACFST were lower than those of natural cooling. Since structures are employed in the elastic phase under normal working conditions, adding basalt fiber can compensate for the compressive stiffness loss caused by recycled aggregate in concrete filled steel tubes after high temperatures. However, the reduction in capacity safety reserves should be considered when designing and post-fire repairing. If circumstances allow, rapid cooling methods, such as water cooling, should be avoided during fire extinguishing to reduce structural strength loss. Eventually, a design model was built to calculate the residual strength, compressive stiffness, and peak strain of the post-fire BF-RACFST short columns.
{"title":"Post-fire compressive performance of basalt fiber recycled aggregate concrete filled steel tube","authors":"Qinglin Jia , Lin Xiao , Heng Liu , Xing Wei , Zhirui Kang","doi":"10.1016/j.jcsr.2024.109164","DOIUrl":"10.1016/j.jcsr.2024.109164","url":null,"abstract":"<div><div>This study reports the results of post-fire axial compressive tests on 87 basalt fiber recycled aggregate concrete (BFRAC) cubes and 25 basalt fiber recycled aggregate concrete filled steel tube (BF-RACFST) short columns. The variables were temperature (20, 300, 500, and 800 °C), recycled aggregate replacement ratio (0, 50, and 100 %), basalt fiber content (0, 4, and 8 kg/m<sup>3</sup>), and cooling method. The specimens were firstly heated at constant high temperatures. After cooling to room temperature, the axial compression tests were conducted. The findings revealed that recycled aggregate prevented explosive spalling of BFRAC but reduced the post-fire capacity and stiffness of BF-RACFST. Adding basalt fiber increased the compressive strength of BFRAC cubes, decreased BF-RACFST post-fire capacity, and slightly increased the post-fire compressive stiffness of the short columns. After cooling in water, the load and failure capacity of BF-RACFST were lower than those of natural cooling. Since structures are employed in the elastic phase under normal working conditions, adding basalt fiber can compensate for the compressive stiffness loss caused by recycled aggregate in concrete filled steel tubes after high temperatures. However, the reduction in capacity safety reserves should be considered when designing and post-fire repairing. If circumstances allow, rapid cooling methods, such as water cooling, should be avoided during fire extinguishing to reduce structural strength loss. Eventually, a design model was built to calculate the residual strength, compressive stiffness, and peak strain of the post-fire BF-RACFST short columns.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109164"},"PeriodicalIF":4.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652343","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}
Pub Date : 2024-11-15DOI: 10.1016/j.jcsr.2024.109163
Ye Tian , Duo Liu , Xudong Chen , Xuyang Wang , Jiandong Zhang
The incorporation of Ultra-High-Performance Concrete (UHPC) in steel-concrete composite beams presents an outstanding solution for reducing crack propagation and enhancing ductility. In this study, three-point bending tests were combined with acoustic emission (AE) and digital image correlation (DIC) diagnostics to study the damage evolution in corrugated steel web I-beam UHPC composite beams. A clustering analysis method based on RA-AF-RC parameters was developed, and b-values and Kolmogorov-Sinai entropy were used for early warning analyses. The findings indicated that UHPC significantly enhanced the crack control capability of corrugated steel web I-beam UHPC composite beams. AE ringing counts and energy clearly indicated distinct, identifiable changes at various damage stages, serving as optimal AE monitoring parameters. AE clustering parameters were determined through principal component analysis and Laplacian scores, with K-means algorithm analysis confirming the alignment with actual crack patterns. K-entropy analyses provided early warnings for cracks, yielding, and failures, showing that b-values can effectively predict structural failures and that K-entropy is also effective in early warnings for structural cracks, yielding, and failures. This AE monitoring method offers a superior alternative to traditional monitoring methods, enabling real-time monitoring and early warning for damage evolution in composite beams.
{"title":"Damage evolution of steel-UHPC composite beams using AE and DIC techniques","authors":"Ye Tian , Duo Liu , Xudong Chen , Xuyang Wang , Jiandong Zhang","doi":"10.1016/j.jcsr.2024.109163","DOIUrl":"10.1016/j.jcsr.2024.109163","url":null,"abstract":"<div><div>The incorporation of Ultra-High-Performance Concrete (UHPC) in steel-concrete composite beams presents an outstanding solution for reducing crack propagation and enhancing ductility. In this study, three-point bending tests were combined with acoustic emission (AE) and digital image correlation (DIC) diagnostics to study the damage evolution in corrugated steel web I-beam UHPC composite beams. A clustering analysis method based on <em>RA</em>-<em>AF</em>-<em>RC</em> parameters was developed, and <em>b</em>-values and Kolmogorov-Sinai entropy were used for early warning analyses. The findings indicated that UHPC significantly enhanced the crack control capability of corrugated steel web I-beam UHPC composite beams. AE ringing counts and energy clearly indicated distinct, identifiable changes at various damage stages, serving as optimal AE monitoring parameters. AE clustering parameters were determined through principal component analysis and Laplacian scores, with <em>K</em>-means algorithm analysis confirming the alignment with actual crack patterns. <em>K</em>-entropy analyses provided early warnings for cracks, yielding, and failures, showing that <em>b</em>-values can effectively predict structural failures and that <em>K</em>-entropy is also effective in early warnings for structural cracks, yielding, and failures. This AE monitoring method offers a superior alternative to traditional monitoring methods, enabling real-time monitoring and early warning for damage evolution in composite beams.</div></div>","PeriodicalId":15557,"journal":{"name":"Journal of Constructional Steel Research","volume":"224 ","pages":"Article 109163"},"PeriodicalIF":4.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652349","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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