Structures最新文献_第6页

Stiffness contributions to the dynamics of a reinforced concrete arch bridge at low amplitude vibrations 刚度对钢筋混凝土拱桥在低振幅振动下的动力特性的贡献

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-22 DOI: 10.1016/j.istruc.2026.111173

Ilenia Rosati , Edwin Reynders , Geert Lombaert , Marco Di Ludovico , Carlo Rainieri

Reinforced concrete upper deck arch bridges are interesting structures from the architectural and structural viewpoint. Indeed, they usually are slender but strong and long-lasting structures able to provide a cost-effective and aesthetically appealing solution to span large distances. Many of those bridges have been designed according to outdated codes and they are close to the end of their lifespan. Thus, enhancing the knowledge about their behavior can contribute to a more accurate structural assessment. Recent recommendations on risk assessment and structural monitoring of existing bridges in Italy emphasize the importance of structural identification for the effective management and maintenance of the national bridge stock. In particular, the Italian Guidelines promote the refinement of numerical models to reduce modeling uncertainties. In this context, Operational Modal Analysis (OMA) provides valuable experimental data to construct representative models of the structural behavior under operational conditions. The present paper focuses on the refinement of a Finite Element (FE) model of a reinforced concrete (r.c.) highway bridge using data obtained from an OMA test. The peculiar structural configuration of the bridge, consisting of a relatively thin and wide vault and an upper collaborative deck, dictates the significance of the application in a structural engineering context. The selected case study is briefly introduced, and execution and results of the OMA test as well as setting of a detailed FE model using Ansys Mechanical ADPL are described afterwards. After having identified the main uncertainties in numerical modeling, model refinement is finally discussed. The main lessons learned from the present application are summarized, remarking the contribution of selected components to the structural stiffness at low amplitude vibrations.

从建筑和结构的角度来看，钢筋混凝土上桥面拱桥是一种有趣的结构。事实上，它们通常是细长但坚固耐用的结构，能够提供一种经济有效且美观的解决方案，可以跨越很远的距离。这些桥梁中的许多都是根据过时的规范设计的，它们的使用寿命已经接近尾声。因此，增强对其行为的了解有助于更准确的结构评估。最近关于意大利现有桥梁的风险评估和结构监测的建议强调了结构鉴定对有效管理和维护国家桥梁存量的重要性。特别是，《意大利准则》促进了数值模式的改进，以减少建模的不确定性。在这种情况下，运行模态分析（OMA）提供了有价值的实验数据来构建具有代表性的结构在运行条件下的行为模型。本文的重点是利用从OMA试验中获得的数据对钢筋混凝土（rc）公路桥梁的有限元（FE）模型进行改进。桥的特殊结构配置，由一个相对薄而宽的拱顶和上部协同甲板组成，决定了在结构工程环境中应用的重要性。简要介绍了选定的案例研究，随后描述了OMA测试的执行和结果，以及使用Ansys Mechanical ADPL建立详细的有限元模型。在确定了数值模拟中的主要不确定因素后，最后讨论了模型的改进问题。总结了从当前应用中获得的主要经验教训，并指出了所选部件对低振幅振动下结构刚度的贡献。

{"title":"Stiffness contributions to the dynamics of a reinforced concrete arch bridge at low amplitude vibrations","authors":"Ilenia Rosati , Edwin Reynders , Geert Lombaert , Marco Di Ludovico , Carlo Rainieri","doi":"10.1016/j.istruc.2026.111173","DOIUrl":"10.1016/j.istruc.2026.111173","url":null,"abstract":"<div><div>Reinforced concrete upper deck arch bridges are interesting structures from the architectural and structural viewpoint. Indeed, they usually are slender but strong and long-lasting structures able to provide a cost-effective and aesthetically appealing solution to span large distances. Many of those bridges have been designed according to outdated codes and they are close to the end of their lifespan. Thus, enhancing the knowledge about their behavior can contribute to a more accurate structural assessment. Recent recommendations on risk assessment and structural monitoring of existing bridges in Italy emphasize the importance of structural identification for the effective management and maintenance of the national bridge stock. In particular, the Italian Guidelines promote the refinement of numerical models to reduce modeling uncertainties. In this context, Operational Modal Analysis (OMA) provides valuable experimental data to construct representative models of the structural behavior under operational conditions. The present paper focuses on the refinement of a Finite Element (FE) model of a reinforced concrete (r.c.) highway bridge using data obtained from an OMA test. The peculiar structural configuration of the bridge, consisting of a relatively thin and wide vault and an upper collaborative deck, dictates the significance of the application in a structural engineering context. The selected case study is briefly introduced, and execution and results of the OMA test as well as setting of a detailed FE model using Ansys Mechanical ADPL are described afterwards. After having identified the main uncertainties in numerical modeling, model refinement is finally discussed. The main lessons learned from the present application are summarized, remarking the contribution of selected components to the structural stiffness at low amplitude vibrations.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111173"},"PeriodicalIF":4.3,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024784","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}

引用次数: 0

Performance prediction of CFST square columns strengthened with square steel tube and sandwiched concrete jackets driven by denoising diffusion probabilistic model 基于去噪扩散概率模型的方钢管夹套加固CFST方柱性能预测

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111162

Zongming Song, Keao Peng, Pengpeng Wang, Yiyan Lu

Square concrete-filled steel tube (CFST) columns strengthened with square steel tube and sandwiched concrete jackets face a significant challenge in data-driven modeling due to the scarcity of experimental data. Although finite element methods (FEM) can be used to generate supplementary data, their reliance on idealized modeling assumptions limits their ability to accurately capture structural responses under realistic conditions. This study proposes a structural performance data synthesis approach based on denoising diffusion probabilistic model (DDPM). A DDPM is designed and optimized using limited experimental data of strengthened CFST square columns, and high-fidelity synthetic samples of structural performance are generated through forward diffusion and reverse denoising processes. To evaluate the validity of the synthetic data, a comparative analysis is conducted with the real experimental data in terms of statistical characteristics and distribution consistency, demonstrating high alignment across multiple feature dimensions. Machine learning (ML) models are then trained and validated under two strategies: training on synthetic data and testing on real data (TSTR), and training and testing on real data (TRTR). Under the TSTR strategy, the best-performing ML model achieves an R² of 0.897 on the real test set, significantly outperforming the 0.536 obtained under the TRTR strategy—representing a 67 % improvement. Meanwhile, the MAE and RMSE are reduced from 273.418 and 354.172–122.962 and 172.707, respectively, with error reductions of 55 % and 51 %. These results indicate that DDPM-generated synthetic data effectively address the shortage of experimental data, substantially improving the accuracy and robustness of load-bearing capacity predictions for strengthened CFST columns, with notably better generalization in real-world scenarios. Furthermore, SHAP analysis is employed to reveal the contributions and influence mechanisms of key input variables. Compared to FEM-based methods that rely on idealized assumptions, the proposed DDPM–ML framework demonstrates superior predictive accuracy and computational efficiency, showing strong potential for engineering applications in structural strengthening performance evaluation.

由于实验数据的缺乏，方形钢管夹套加固方形钢管混凝土柱在数据驱动建模方面面临着巨大的挑战。虽然有限元方法（FEM）可用于生成补充数据，但它们对理想化建模假设的依赖限制了它们在现实条件下准确捕获结构响应的能力。提出了一种基于去噪扩散概率模型（DDPM）的结构性能数据综合方法。利用有限的加固CFST方柱实验数据，设计并优化了DDPM，并通过正向扩散和反向去噪处理生成了高保真的结构性能合成样本。为了评估合成数据的有效性，将其与真实实验数据在统计特征和分布一致性方面进行了对比分析，结果表明，合成数据在多个特征维度上具有较高的一致性。然后，机器学习（ML）模型在两种策略下进行训练和验证：在合成数据上进行训练和在真实数据上进行测试（TSTR），以及在真实数据上进行训练和测试（TRTR）。在TSTR策略下，表现最好的ML模型在真实测试集上的R²为0.897，显著优于TRTR策略下的0.536，提高了67 %。同时，MAE和RMSE分别从273.418和354.172减小到122.962和172.707，误差减小了55 %和51 %。这些结果表明，ddpm生成的综合数据有效地解决了实验数据的不足，大大提高了加固CFST柱承载力预测的准确性和鲁棒性，在实际场景中具有明显更好的泛化能力。此外，利用SHAP分析揭示了关键输入变量的贡献和影响机制。与基于fem的方法相比，基于理想化假设的DDPM-ML框架具有更高的预测精度和计算效率，在结构强化性能评估方面具有强大的工程应用潜力。

{"title":"Performance prediction of CFST square columns strengthened with square steel tube and sandwiched concrete jackets driven by denoising diffusion probabilistic model","authors":"Zongming Song, Keao Peng, Pengpeng Wang, Yiyan Lu","doi":"10.1016/j.istruc.2026.111162","DOIUrl":"10.1016/j.istruc.2026.111162","url":null,"abstract":"<div><div>Square concrete-filled steel tube (CFST) columns strengthened with square steel tube and sandwiched concrete jackets face a significant challenge in data-driven modeling due to the scarcity of experimental data. Although finite element methods (FEM) can be used to generate supplementary data, their reliance on idealized modeling assumptions limits their ability to accurately capture structural responses under realistic conditions. This study proposes a structural performance data synthesis approach based on denoising diffusion probabilistic model (DDPM). A DDPM is designed and optimized using limited experimental data of strengthened CFST square columns, and high-fidelity synthetic samples of structural performance are generated through forward diffusion and reverse denoising processes. To evaluate the validity of the synthetic data, a comparative analysis is conducted with the real experimental data in terms of statistical characteristics and distribution consistency, demonstrating high alignment across multiple feature dimensions. Machine learning (ML) models are then trained and validated under two strategies: training on synthetic data and testing on real data (TSTR), and training and testing on real data (TRTR). Under the TSTR strategy, the best-performing ML model achieves an R² of 0.897 on the real test set, significantly outperforming the 0.536 obtained under the TRTR strategy—representing a 67 % improvement. Meanwhile, the MAE and RMSE are reduced from 273.418 and 354.172–122.962 and 172.707, respectively, with error reductions of 55 % and 51 %. These results indicate that DDPM-generated synthetic data effectively address the shortage of experimental data, substantially improving the accuracy and robustness of load-bearing capacity predictions for strengthened CFST columns, with notably better generalization in real-world scenarios. Furthermore, SHAP analysis is employed to reveal the contributions and influence mechanisms of key input variables. Compared to FEM-based methods that rely on idealized assumptions, the proposed DDPM–ML framework demonstrates superior predictive accuracy and computational efficiency, showing strong potential for engineering applications in structural strengthening performance evaluation.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111162"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024778","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}

引用次数: 0

Optimal seismic design of hysteretic damper strengthened steel frame based on ANN model 基于神经网络模型的滞回阻尼器加固钢框架抗震优化设计

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111132

Lei Guo , Wenyuan Xu , Tianhao Yu , Dan Xu , Jingfeng Wang , Wanqian Wang

Hysteretic damper is widely used as energy dissipation device to enhance the seismic performance of existing structures. However, current studies paid little attention to make the hysteretic damper to dissipate seismic energy as much as possible. This paper proposed an optimal design method to ensure the hysteretic damper dissipate seismic energy as much as possible for enhancing the seismic performance of existing steel frames. Initially, the equivalent single degree of freedom (ESDOF) was established using two nonlinear springs representing the frame and hysteretic damper, respectively. Two additional parameters, strength and displacement ratios, were considered to reveal the influence of hysteretic damper. Parametric analysis was performed to detect the influence of structural and hysteretic parameters on the hysteretic energy of frame to total input seismic energy ratio (E_f/E_t) based on the ESDOF. It indicated that the strength and displacement ratios had significant influence on E_f/E_t. ANN model was employed to handle the complex nonlinear regression problem for predicting E_f/E_t considering substantial parameters. Different training algorithm, activate function and input parameters were considered to tune the ANN model for achieving best performance. Afterwards, an optimal design method was proposed to achieve lowest E_f/E_t considering the story drift limits under design based and maximum considered earthquakes, in which the fitness function was directly calculated by ANN model. Three prototype structures were designed based on the proposed optimal design method. Through the time history analysis, it revealed that the designed structures were complied with the design objectives, which validated that the proposed seismic design method is effective and reasonable.

滞回阻尼器作为一种耗能装置，被广泛应用于提高既有结构的抗震性能。然而，目前的研究很少关注如何使滞回阻尼器尽可能地耗散地震能量。为提高既有钢框架的抗震性能，提出了一种使滞回阻尼器最大限度地耗散地震能量的优化设计方法。首先，用两个非线性弹簧分别代表车架和滞回阻尼器建立等效单自由度（ESDOF）。考虑了两个附加参数，强度和位移比，以揭示迟滞阻尼器的影响。基于ESDOF进行参数分析，检测结构参数和滞回参数对框架滞回能与总输入地震能比（Ef/Et）的影响。结果表明，强度比和位移比对Ef/Et有显著影响。采用人工神经网络模型处理复杂的非线性回归问题，在考虑大量参数的情况下预测Ef/Et。考虑了不同的训练算法、激活函数和输入参数，对神经网络模型进行了调整，使其达到最佳性能。在此基础上，提出了一种基于设计的考虑楼层漂移限制的最小Ef/Et和考虑地震的最大Ef/Et的优化设计方法，其中适应度函数由人工神经网络模型直接计算。基于所提出的优化设计方法，设计了三个原型结构。通过时程分析，表明所设计的结构符合设计目标，验证了所提出的抗震设计方法的有效性和合理性。

{"title":"Optimal seismic design of hysteretic damper strengthened steel frame based on ANN model","authors":"Lei Guo , Wenyuan Xu , Tianhao Yu , Dan Xu , Jingfeng Wang , Wanqian Wang","doi":"10.1016/j.istruc.2026.111132","DOIUrl":"10.1016/j.istruc.2026.111132","url":null,"abstract":"<div><div>Hysteretic damper is widely used as energy dissipation device to enhance the seismic performance of existing structures. However, current studies paid little attention to make the hysteretic damper to dissipate seismic energy as much as possible. This paper proposed an optimal design method to ensure the hysteretic damper dissipate seismic energy as much as possible for enhancing the seismic performance of existing steel frames. Initially, the equivalent single degree of freedom (ESDOF) was established using two nonlinear springs representing the frame and hysteretic damper, respectively. Two additional parameters, strength and displacement ratios, were considered to reveal the influence of hysteretic damper. Parametric analysis was performed to detect the influence of structural and hysteretic parameters on the hysteretic energy of frame to total input seismic energy ratio (<em>E</em><sub>f</sub>/<em>E</em><sub>t</sub>) based on the ESDOF. It indicated that the strength and displacement ratios had significant influence on <em>E</em><sub>f</sub>/<em>E</em><sub>t</sub>. ANN model was employed to handle the complex nonlinear regression problem for predicting <em>E</em><sub>f</sub>/<em>E</em><sub>t</sub> considering substantial parameters. Different training algorithm, activate function and input parameters were considered to tune the ANN model for achieving best performance. Afterwards, an optimal design method was proposed to achieve lowest <em>E</em><sub>f</sub>/<em>E</em><sub>t</sub> considering the story drift limits under design based and maximum considered earthquakes, in which the fitness function was directly calculated by ANN model. Three prototype structures were designed based on the proposed optimal design method. Through the time history analysis, it revealed that the designed structures were complied with the design objectives, which validated that the proposed seismic design method is effective and reasonable.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111132"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024779","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}

引用次数: 0

Seismic performance of concrete-encased CFST column to exterior wide-flat beam joint 包混凝土CFST柱与外宽扁梁节点的抗震性能研究

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111078

Linlin Song , Mingyang Wei , Xueming Zhang , Kun Liu , Hangdong Yang

To study the seismic performance of concrete-encased concrete-filled steel tubular (CFST) column-to-exterior wide-flat beam joints, both types of specimens—concrete-encased CFST column joints (CCFSTCJ) and standard CFST column joints (CFSTCJ)—were designed based on the principle of equivalent flexural stiffness. A combined research method involving quasi-static tests and finite element (FE) simulations was adopted to systematically investigate the seismic behavior of the joints. Additionally, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed for quantitative performance evaluation. Experimental results indicated that both types of joints exhibited flexural failure at the beam ends. Compared to CFSTCJ, CCFSTCJ demonstrated a 6.54 % reduction in ultimate load capacity and a 3.5 % decrease in stiffness degradation, while achieving a 21.43 % increase in the equivalent viscous damping ratio and a 25.6 % improvement in ductility. The accuracy of the finite element model was verified based on the experimental results. The TOPSIS evaluation indicated that CCFSTCJ exhibited superior overall seismic performance despite the minor reductions in load-bearing capacity. This study provides a reliable experimental and numerical basis for the application of concrete-encased CFST column-wide-flat beam joints in underground structures.

为研究钢管混凝土柱-外宽扁梁节点的抗震性能，基于等效抗弯刚度原理设计了钢管混凝土柱节点（CCFSTCJ）和标准钢管混凝土柱节点。采用拟静力试验与有限元模拟相结合的研究方法，系统地研究了节点的抗震性能。此外，采用理想解相似偏好排序法（TOPSIS）进行定量绩效评价。试验结果表明，两种节点在梁端均出现弯曲破坏。与CFSTCJ相比，CCFSTCJ的极限承载能力降低了6.54 %，刚度退化降低了3.5 %，等效粘性阻尼比提高了21.43 %，延性提高了25.6 %。基于实验结果验证了有限元模型的准确性。TOPSIS评价表明，尽管CCFSTCJ的承载能力略有下降，但其整体抗震性能仍较好。该研究为钢管混凝土包壳柱-宽扁梁节点在地下结构中的应用提供了可靠的实验和数值依据。

{"title":"Seismic performance of concrete-encased CFST column to exterior wide-flat beam joint","authors":"Linlin Song , Mingyang Wei , Xueming Zhang , Kun Liu , Hangdong Yang","doi":"10.1016/j.istruc.2026.111078","DOIUrl":"10.1016/j.istruc.2026.111078","url":null,"abstract":"<div><div>To study the seismic performance of concrete-encased concrete-filled steel tubular (CFST) column-to-exterior wide-flat beam joints, both types of specimens—concrete-encased CFST column joints (CCFSTCJ) and standard CFST column joints (CFSTCJ)—were designed based on the principle of equivalent flexural stiffness. A combined research method involving quasi-static tests and finite element (FE) simulations was adopted to systematically investigate the seismic behavior of the joints. Additionally, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed for quantitative performance evaluation. Experimental results indicated that both types of joints exhibited flexural failure at the beam ends. Compared to CFSTCJ, CCFSTCJ demonstrated a 6.54 % reduction in ultimate load capacity and a 3.5 % decrease in stiffness degradation, while achieving a 21.43 % increase in the equivalent viscous damping ratio and a 25.6 % improvement in ductility. The accuracy of the finite element model was verified based on the experimental results. The TOPSIS evaluation indicated that CCFSTCJ exhibited superior overall seismic performance despite the minor reductions in load-bearing capacity. This study provides a reliable experimental and numerical basis for the application of concrete-encased CFST column-wide-flat beam joints in underground structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111078"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024454","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}

引用次数: 0

Hysteretic behavior of pitting-corroded concrete-filled steel tube columns with different strengthened approaches 不同加固方式下点蚀钢管混凝土柱的滞回特性

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111148

Feiyu Liao , Yucheng Cui , Yuxing Yang , Muxin Lin , Ying Wang

This study presents an experimental and numerical investigation of the hysteretic behavior of pitting-corroded concrete-filled steel tube (CFST) columns and the efficacy of two reinforcement methods: Carbon Fiber Reinforced Polymer (CFRP) wrapping and Ultra-High-Performance Concrete (UHPC) encasement. Eleven column specimens were tested under constant axial compression and cyclic lateral loading. The influence of pitting corrosion depth and reinforcement type on the failure modes, load-carrying capacity, stiffness, and energy dissipation was examined. Validated numerical analyses were conducted to investigate load transfer mechanisms and perform parametric studies on key geometric and material properties. Based on the findings, modified design equations were developed to predict the load-carrying capacity of corroded and reinforced CFST columns. The results demonstrate that CFRP wrapping exhibits superior performance in enhancing specimen ductility, while UHPC encasement demonstrates significant effectiveness in restoring load-carrying capacity, with capacity and stiffness values exceeding those of the original un-corroded specimen. The findings provide a reliable basis for the seismic assessment and design of repaired CFST columns in corrosive environments.

本文对钢管混凝土（CFST）柱的点蚀迟滞特性进行了试验和数值研究，并对碳纤维增强聚合物（CFRP）包裹和超高性能混凝土（UHPC）包裹两种加固方法的效果进行了研究。对11根柱试件进行了恒定轴压和循环侧向加载试验。考察了点蚀深度和钢筋类型对破坏模式、承载能力、刚度和耗能的影响。对载荷传递机制进行了有效的数值分析，并对关键几何和材料特性进行了参数化研究。在此基础上，建立了修正的设计方程来预测腐蚀和加筋的钢管混凝土柱的承载能力。结果表明，CFRP包覆在提高试件延性方面表现出优异的性能，而UHPC包覆在恢复承载力方面表现出显著的效果，其承载力和刚度值均超过原始未腐蚀试件。研究结果为腐蚀环境下钢管混凝土修复柱的抗震评估和设计提供了可靠的依据。

{"title":"Hysteretic behavior of pitting-corroded concrete-filled steel tube columns with different strengthened approaches","authors":"Feiyu Liao , Yucheng Cui , Yuxing Yang , Muxin Lin , Ying Wang","doi":"10.1016/j.istruc.2026.111148","DOIUrl":"10.1016/j.istruc.2026.111148","url":null,"abstract":"<div><div>This study presents an experimental and numerical investigation of the hysteretic behavior of pitting-corroded concrete-filled steel tube (CFST) columns and the efficacy of two reinforcement methods: Carbon Fiber Reinforced Polymer (CFRP) wrapping and Ultra-High-Performance Concrete (UHPC) encasement. Eleven column specimens were tested under constant axial compression and cyclic lateral loading. The influence of pitting corrosion depth and reinforcement type on the failure modes, load-carrying capacity, stiffness, and energy dissipation was examined. Validated numerical analyses were conducted to investigate load transfer mechanisms and perform parametric studies on key geometric and material properties. Based on the findings, modified design equations were developed to predict the load-carrying capacity of corroded and reinforced CFST columns. The results demonstrate that CFRP wrapping exhibits superior performance in enhancing specimen ductility, while UHPC encasement demonstrates significant effectiveness in restoring load-carrying capacity, with capacity and stiffness values exceeding those of the original un-corroded specimen. The findings provide a reliable basis for the seismic assessment and design of repaired CFST columns in corrosive environments.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111148"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024458","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}

引用次数: 0

Experimental study and time-varying modeling on stress relaxation of full locked steel cable 全锁紧钢索应力松弛的试验研究及时变建模

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111109

Yutong Zhang , Zhihua Chen , Liulu Guo , Hongbo Liu , Yansheng Du

The full locked steel cable (FLSC) is being widely used in various prestressed cable structures. FLSC achieves a higher cross-section steel content and sealing by interlocking the outer Z-shaped steel wires to form a locking layer. To investigate the stress relaxation behavior of FLSC, this study carried out 120-hour short-term stress relaxation tests at different temperatures and initial stress ratios for FLSC, Z-shaped steel wires, and round steel wires. The test results revealed that the stress relaxation rate of the specimens rose rapidly at first and then increased slowly over time. The stress relaxation rate increased with the increase of temperature and the initial stress ratio. The empirical model of logarithmic function describing the short-term stress relaxation-time curves at different initial stress ratios and ambient temperatures is obtained by proposing a bivariate function. The non-uniform stress relaxation mechanism of different layers of steel wires in FLSC was discovered by finite element modelling. Finally, the Kelvin chain solid viscoelastic (KCSV) model for steel cable is presented based on viscoelastic theory. The calculation method for predicting the long-term stress relaxation rate is proposed based on the KCSV model and the short-term relaxation data. The 50-year stress relaxation rate of FLSC can achieve 12.18 % under the most unfavourable service conditions of building cable (initial stress ratio=55 %, temperature=40°C).

全锁紧钢索在各种预应力索结构中得到了广泛的应用。FLSC通过外部z形钢丝互锁形成锁紧层，实现了更高的截面含钢量和密封性。为了研究FLSC的应力松弛行为，本研究对FLSC、z形钢丝和圆钢丝进行了不同温度和初始应力比下的120小时短期应力松弛试验。试验结果表明，随着时间的推移，试件的应力松弛速率先快速上升，后缓慢上升。应力松弛速率随温度的升高和初始应力比的增大而增大。通过提出二元函数，得到了描述不同初始应力比和环境温度下短期应力松弛-时间曲线的对数函数经验模型。通过有限元模拟，发现了FLSC中不同层钢丝的非均匀应力松弛机制。最后，基于粘弹性理论建立了钢索的开尔文链固体粘弹性模型。提出了基于KCSV模型和短期应力松弛数据的长期应力松弛率预测计算方法。在最不利的建筑索使用条件下（初始应力比为55 %，温度为40℃），FLSC的50年应力松弛率可达12.18 %。

{"title":"Experimental study and time-varying modeling on stress relaxation of full locked steel cable","authors":"Yutong Zhang , Zhihua Chen , Liulu Guo , Hongbo Liu , Yansheng Du","doi":"10.1016/j.istruc.2026.111109","DOIUrl":"10.1016/j.istruc.2026.111109","url":null,"abstract":"<div><div>The full locked steel cable (FLSC) is being widely used in various prestressed cable structures. FLSC achieves a higher cross-section steel content and sealing by interlocking the outer Z-shaped steel wires to form a locking layer. To investigate the stress relaxation behavior of FLSC, this study carried out 120-hour short-term stress relaxation tests at different temperatures and initial stress ratios for FLSC, Z-shaped steel wires, and round steel wires. The test results revealed that the stress relaxation rate of the specimens rose rapidly at first and then increased slowly over time. The stress relaxation rate increased with the increase of temperature and the initial stress ratio. The empirical model of logarithmic function describing the short-term stress relaxation-time curves at different initial stress ratios and ambient temperatures is obtained by proposing a bivariate function. The non-uniform stress relaxation mechanism of different layers of steel wires in FLSC was discovered by finite element modelling. Finally, the Kelvin chain solid viscoelastic (KCSV) model for steel cable is presented based on viscoelastic theory. The calculation method for predicting the long-term stress relaxation rate is proposed based on the KCSV model and the short-term relaxation data. The 50-year stress relaxation rate of FLSC can achieve 12.18 % under the most unfavourable service conditions of building cable (initial stress ratio=55 %, temperature=40°C).</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111109"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024776","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}

引用次数: 0

A novel full-field strain analysis for evaluating fracture energy and structural integrity of fiber-cement composites 一种新的评价纤维-水泥复合材料断裂能和结构完整性的全场应变分析方法

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111158

Jianchao Zhang , Hongxi Liu , Zejian Lin , Ying Gao , Wan-qian Li , Biqin Dong , Feng Xing , Yu Zheng

Improving the accurate determination of the fracture energies in cementitious composites is highly significant for engineering practice. This research employed X-ray computed tomography (XCT) and digital volume correlation (DVC) to investigate fracture behavior in fiber-cement composites. In-situ XCT loading experiments were conducted for tracking failure progression, facilitating three-dimensional volume image reconstruction. The internal volumetric strains of the samples were calculated by DVC based on the volume images before and after deformation, enabling computation of deformation energies outside the fracture domains. The fracture energies of the samples were obtained after taking the deformation energy into account. The outcomes showed that the fracture energy will be overestimated by about 10 % (the value will increase for fiber reinforced materials) when the deformation energy is not considered.

提高胶凝复合材料断裂能的准确测定对工程实践具有重要意义。本研究采用x射线计算机断层扫描（XCT）和数字体积相关（DVC）来研究纤维-水泥复合材料的断裂行为。现场进行XCT加载实验，跟踪破坏进程，便于三维体像重建。基于变形前后的体积图像，通过DVC计算试样的内部体积应变，从而计算断裂域外的变形能。考虑变形能后得到试样的断裂能。结果表明，在不考虑变形能的情况下，断裂能将被高估约10 %（纤维增强材料的数值会增大）。

引用次数: 0

The knowledge-driven intelligent diagnosis and monitoring of spatial joint security status 基于知识驱动的空间联合安全状态智能诊断与监测

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-21 DOI: 10.1016/j.istruc.2026.111150

Jinxin Kuang , Zhiming Hao , Naixian Li , Hao Chen , Jicheng Li

Prefabricated connection structures are extensively applied in major engineering projects, where joint safety critically governs overall structural performance. Existing studies have largely overlooked the multi-axial coupling failure behavior of spatial joints, resulting in oversimplified models that fail to capture their true mechanical response under realistic loading. This paper proposes an interdisciplinary, knowledge-driven safety assessment framework that integrates physical mechanisms with data-driven approaches. An experimentally calibrated finite element model was developed to systematically analyze the nonlinear degradation of spatial beam-column and bolted sphere joints under complex moment loading, revealing stress redistribution patterns, stiffness degradation, and mechanistically interpretable multi-axial coupling failure mechanisms. A quasi-ellipsoidal failure function grounded in mechanical principles was formulated and embedded into physics-informed neural networks, enabling high-precision prediction of joint safety states. A composite loss function incorporating monotonicity constraints and regularization terms, combined with a simulated annealing strategy for parameter identification, significantly enhances model generalization and physical consistency under sparse data conditions. Furthermore, an intelligent integrated safety assessment system was implemented, featuring parallel multi-joint analysis, 3D failure surface visualization, and hierarchical warning functions for closed-loop management from single-joint diagnosis to system-level health monitoring. The method accurately identifies critical shape parameters and unveils anisotropic coupling effects, while providing intuitive, color-coded decision support for engineers. This work delivers high-fidelity, interpretable, and physically consistent core components for digital twin systems of prefabricated infrastructure.

装配式连接结构在重大工程中得到了广泛的应用，在这些工程中，节点的安全对结构的整体性能起着至关重要的作用。现有的研究在很大程度上忽略了空间节点的多轴耦合破坏行为，导致模型过于简化，无法捕捉其在实际载荷下的真实力学响应。本文提出了一个跨学科的、知识驱动的安全评估框架，该框架将物理机制与数据驱动的方法相结合。建立了一个实验校准的有限元模型，系统地分析了复杂弯矩载荷下空间梁柱和螺栓球体节点的非线性退化，揭示了应力重分布模式、刚度退化以及多轴耦合破坏机制。建立了基于力学原理的准椭球破坏函数，并将其嵌入到物理信息神经网络中，实现了对关节安全状态的高精度预测。结合单调性约束和正则化项的复合损失函数，结合参数识别的模拟退火策略，显著提高了稀疏数据条件下模型的泛化和物理一致性。实现了具有多关节并行分析、三维故障面可视化和分层预警功能的智能综合安全评估系统，实现了从单关节诊断到系统级健康监测的闭环管理。该方法可准确识别关键形状参数，揭示各向异性耦合效应，同时为工程师提供直观的彩色编码决策支持。这项工作为预制基础设施的数字孪生系统提供了高保真、可解释和物理一致的核心组件。

{"title":"The knowledge-driven intelligent diagnosis and monitoring of spatial joint security status","authors":"Jinxin Kuang , Zhiming Hao , Naixian Li , Hao Chen , Jicheng Li","doi":"10.1016/j.istruc.2026.111150","DOIUrl":"10.1016/j.istruc.2026.111150","url":null,"abstract":"<div><div>Prefabricated connection structures are extensively applied in major engineering projects, where joint safety critically governs overall structural performance. Existing studies have largely overlooked the multi-axial coupling failure behavior of spatial joints, resulting in oversimplified models that fail to capture their true mechanical response under realistic loading. This paper proposes an interdisciplinary, knowledge-driven safety assessment framework that integrates physical mechanisms with data-driven approaches. An experimentally calibrated finite element model was developed to systematically analyze the nonlinear degradation of spatial beam-column and bolted sphere joints under complex moment loading, revealing stress redistribution patterns, stiffness degradation, and mechanistically interpretable multi-axial coupling failure mechanisms. A quasi-ellipsoidal failure function grounded in mechanical principles was formulated and embedded into physics-informed neural networks, enabling high-precision prediction of joint safety states. A composite loss function incorporating monotonicity constraints and regularization terms, combined with a simulated annealing strategy for parameter identification, significantly enhances model generalization and physical consistency under sparse data conditions. Furthermore, an intelligent integrated safety assessment system was implemented, featuring parallel multi-joint analysis, 3D failure surface visualization, and hierarchical warning functions for closed-loop management from single-joint diagnosis to system-level health monitoring. The method accurately identifies critical shape parameters and unveils anisotropic coupling effects, while providing intuitive, color-coded decision support for engineers. This work delivers high-fidelity, interpretable, and physically consistent core components for digital twin systems of prefabricated infrastructure.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111150"},"PeriodicalIF":4.3,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024459","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}

引用次数: 0

Seismic performance of concentrically braced frames considering the braced-beam yielding (long-link EBF) mechanism 考虑支撑梁屈服（长连杆EBF）机制的同心支撑框架的抗震性能

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-20 DOI: 10.1016/j.istruc.2026.111156

Zhi-Qian Dong , Cheng Zhou , Gang Li , Tian-Hao Zhang , Hao Zhang , Hui-Dong Liu

Under seismic loading, partial failure of braces in steel chevron concentrically braced frames may lead to the development of a braced beam yielding mechanism, also known as the long-link eccentrically braced frame mechanism, which has not been adequately addressed in previous studies. To investigate the influence of this mechanism on the structural collapse resistance, two 6-story concentrically braced frame models with identical and varied parameters for tension and compression braces were designed, respectively. Twenty far-field ground motions were used to conduct incremental dynamic analysis on the two concentrically braced frame structures. The differences in the collapse performance of the structure with and without considering braced beam yielding mechanism were compared, and the damage evolution process of the concentrically braced frame was analyzed. The collapse resistance performance of the concentrically braced frame considering braced beam yielding mechanism was increased. By varying the stiffness of the braced beam in the concentrically braced frame structure, the influence of the braced beam stiffness on the collapse resistance capacity of the concentrically braced frame was explored, and the influence of the braced beam stiffness on the formation of the braced beam yielding mechanism was subsequently studied. A relatively high stiffness is not conducive to the formation of this mechanism and will reduce the collapse resistant capacity of the structure. Therefore, it is essential to account for the braced beam yielding mechanism in the seismic performance analysis of low-ductility concentrically braced frames, since neglecting it may result in an underestimation of the collapse resistance performance of concentrically braced frames.

在地震荷载作用下，钢形同心支撑框架的支撑部分破坏可能导致支撑梁屈服机制的发展，也称为长杆偏心支撑框架机制，这在以往的研究中没有得到充分的解决。为了研究这一机制对结构抗倒塌能力的影响，设计了两个具有相同拉撑参数和不同压撑参数的6层同心支撑框架模型。采用20次远场地震动对两个同心支撑框架结构进行了增量动力分析。比较了考虑和不考虑支撑梁屈服机理时结构的倒塌性能差异，分析了同心支撑框架的损伤演化过程。考虑支撑梁屈服机理，提高了同心支撑框架的抗倒塌性能。通过改变同心支撑框架结构中支撑梁的刚度，探讨了支撑梁刚度对同心支撑框架抗倒塌能力的影响，进而研究了支撑梁刚度对支撑梁屈服机理形成的影响。较高的刚度不利于这一机制的形成，会降低结构的抗倒塌能力。因此，在低延性同心支撑框架的抗震性能分析中，考虑支撑梁屈服机理是至关重要的，因为忽略它可能会导致对同心支撑框架抗倒塌性能的低估。

{"title":"Seismic performance of concentrically braced frames considering the braced-beam yielding (long-link EBF) mechanism","authors":"Zhi-Qian Dong , Cheng Zhou , Gang Li , Tian-Hao Zhang , Hao Zhang , Hui-Dong Liu","doi":"10.1016/j.istruc.2026.111156","DOIUrl":"10.1016/j.istruc.2026.111156","url":null,"abstract":"<div><div>Under seismic loading, partial failure of braces in steel chevron concentrically braced frames may lead to the development of a braced beam yielding mechanism, also known as the long-link eccentrically braced frame mechanism, which has not been adequately addressed in previous studies. To investigate the influence of this mechanism on the structural collapse resistance, two 6-story concentrically braced frame models with identical and varied parameters for tension and compression braces were designed, respectively. Twenty far-field ground motions were used to conduct incremental dynamic analysis on the two concentrically braced frame structures. The differences in the collapse performance of the structure with and without considering braced beam yielding mechanism were compared, and the damage evolution process of the concentrically braced frame was analyzed. The collapse resistance performance of the concentrically braced frame considering braced beam yielding mechanism was increased. By varying the stiffness of the braced beam in the concentrically braced frame structure, the influence of the braced beam stiffness on the collapse resistance capacity of the concentrically braced frame was explored, and the influence of the braced beam stiffness on the formation of the braced beam yielding mechanism was subsequently studied. A relatively high stiffness is not conducive to the formation of this mechanism and will reduce the collapse resistant capacity of the structure. Therefore, it is essential to account for the braced beam yielding mechanism in the seismic performance analysis of low-ductility concentrically braced frames, since neglecting it may result in an underestimation of the collapse resistance performance of concentrically braced frames.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111156"},"PeriodicalIF":4.3,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024449","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}

引用次数: 0

Experimental investigation on shear mechanical properties of engineering bamboo scrimber 工程竹材剪切力学性能试验研究

IF 4.3 2区工程技术 Q1 ENGINEERING, CIVIL

Structures

Pub Date : 2026-01-20 DOI: 10.1016/j.istruc.2026.111145

Mingtao Wu , Lidan Mei , Xiaoying Luo , Tong Wang , Nan Guo , Yan Zhao

Bamboo scrimber (BS), a high-performance and sustainable engineered bamboo product, has demonstrated strong potential for structural applications. However, its anisotropic shear behaviors remain inadequately understood, posing challenges to the effective design of BS structural components. This study systematically investigated the shear properties of BS through 250 shear tests conducted under five distinct loading orientations. Various failure modes and corresponding shear responses were identified and categorized, revealing a strong correlation between loading direction and mechanical performance. Based on the experimental results, shear strength and shear modulus distributions were quantified, revealing significant anisotropy with average shear strengths ranging from 12.93 to 37.63 MPa and modulus from 213.6 to 606.3 MPa across orientations. Directional design values (6.33–32.58 MPa) were derived using both Normal and Weibull statistical models. Comparative analysis against conventional materials (e.g., concrete, timber, and laminated bamboo) highlights the superior specific shear strength of BS. Accordingly, design recommendations are proposed to accommodate directional shear behavior, providing practical guidance for the application of BS in shear-critical structural elements. These findings support performance-based design approaches and the broader standardization of engineered bamboo structures.

竹纤维（BS）是一种高性能和可持续的工程竹材，在结构应用方面具有很强的潜力。然而，对其各向异性剪切行为的了解还不够充分，这给BS结构构件的有效设计带来了挑战。本研究通过在5种不同加载方向下进行250次剪切试验，系统研究了BS的剪切性能。对不同的破坏模式和相应的剪切响应进行了识别和分类，揭示了加载方向与力学性能之间的强相关性。在此基础上，定量分析了剪切强度和剪切模量的分布，发现各向异性显著，平均剪切强度在12.93 ~ 37.63 MPa之间，模量在213.6 ~ 606.3 MPa之间。方向设计值（6.33-32.58 MPa）采用正态和威布尔统计模型。与传统材料（如混凝土、木材和层压竹子）的对比分析突出了BS优越的比抗剪强度。据此，提出了适应定向剪切行为的设计建议，为BS在剪切临界结构构件中的应用提供了实践指导。这些发现支持基于性能的设计方法和更广泛的工程竹结构标准化。

{"title":"Experimental investigation on shear mechanical properties of engineering bamboo scrimber","authors":"Mingtao Wu , Lidan Mei , Xiaoying Luo , Tong Wang , Nan Guo , Yan Zhao","doi":"10.1016/j.istruc.2026.111145","DOIUrl":"10.1016/j.istruc.2026.111145","url":null,"abstract":"<div><div>Bamboo scrimber (BS), a high-performance and sustainable engineered bamboo product, has demonstrated strong potential for structural applications. However, its anisotropic shear behaviors remain inadequately understood, posing challenges to the effective design of BS structural components. This study systematically investigated the shear properties of BS through 250 shear tests conducted under five distinct loading orientations. Various failure modes and corresponding shear responses were identified and categorized, revealing a strong correlation between loading direction and mechanical performance. Based on the experimental results, shear strength and shear modulus distributions were quantified, revealing significant anisotropy with average shear strengths ranging from 12.93 to 37.63 MPa and modulus from 213.6 to 606.3 MPa across orientations. Directional design values (6.33–32.58 MPa) were derived using both Normal and Weibull statistical models. Comparative analysis against conventional materials (e.g., concrete, timber, and laminated bamboo) highlights the superior specific shear strength of BS. Accordingly, design recommendations are proposed to accommodate directional shear behavior, providing practical guidance for the application of BS in shear-critical structural elements. These findings support performance-based design approaches and the broader standardization of engineered bamboo structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111145"},"PeriodicalIF":4.3,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024455","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}

引用次数: 0