Engineering Structures最新文献_第5页

Blast response and multi-objective optimization of multi-layered kirigami corrugated sandwich panels

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120045

Hao Liu , Zengshen Yue , Rui Zhang , Jiawei Lu , Jian Zhu

The threat of blasts has a devastating effect on vehicles, buildings, and even human lives, creating a pressing need for the development of blast protection systems. A novel multi-layered kirigami corrugated (MKC) sandwich panel has been proposed, featuring kirigami corrugated cores with different geometries in layers while maintaining the same mass, to investigate its blast-resistance performance. The dynamic response of MKC sandwich panels in seven configurations subjected to blast loading was numerically studied via finite element simulations, with their dynamic deformation evolution, deformation/failure modes, panel deflections, and core compression systematically analyzed. The results indicate that the dynamic deformation process of MKC sandwich panels can be approximately decoupled into four stages. The deformation and failure modes of the panels and the formation of plastic hinges in each part of the cell were further analyzed. Moreover, rear panel deflections are found to be significantly influenced by the multi-layer arrangement of the structure. Compared with the original configuration, adjusting the core layer configuration could reduce the peak deflection by 41 %, indicating the ability of multi-layer design to regulate the structural blast resistance. Designing the core at the rear side to be stronger significantly improves the structure’s blast resistance. Subsequently, the response of MKC sandwich panels was modeled using a surrogate modeling technique, with its model accuracy validated. A high-efficiency optimization procedure factoring structural deformation resistance and energy absorption performance of the MKC sandwich panels was proposed by coupling the surrogate model with the NSGA-II algorithm. The optimal sandwich panel has a reduced rear panel peak deformation by up to 55.7 % while increasing specific energy absorption by approximately 15.8 % compared with the preliminary design. This optimized core layer arrangement strategy can significantly enhance the performance of multi-layer structures, while ensuring the convenience of fabrication and improving the material utilization efficiency.

爆炸威胁对车辆、建筑物甚至人的生命都具有毁灭性影响，因此迫切需要开发爆炸防护系统。为了研究新型多层叽里胶波纹（MKC）夹层板的抗爆性能，我们提出了一种新型多层叽里胶波纹（MKC）夹层板，其特点是在保持相同质量的情况下，各层具有不同几何形状的叽里胶波纹芯材。通过有限元模拟，对七种结构的 MKC 夹层板在承受爆炸荷载时的动态响应进行了数值研究，系统分析了它们的动态变形演变、变形/失效模式、板挠度和芯材压缩。结果表明，MKC 夹层板的动态变形过程可近似解耦为四个阶段。进一步分析了面板的变形和失效模式以及单元各部分塑性铰链的形成。此外，还发现后面板挠度受多层结构布置的影响很大。与原始结构相比，调整核心层结构可使峰值挠度降低 41%，这表明多层设计具有调节结构抗爆性的能力。将后侧的核心层设计得更坚固，可显著提高结构的抗爆性能。随后，使用代用建模技术对 MKC 夹层板的响应进行了建模，并验证了其建模精度。通过将代用模型与 NSGA-II 算法耦合，提出了一种将 MKC 夹层板的结构变形阻力和能量吸收性能考虑在内的高效优化程序。与初步设计相比，最优夹芯板的后面板峰值变形减少了 55.7%，而比能量吸收增加了约 15.8%。这种优化的芯层布置策略可显著提高多层结构的性能，同时确保制造的便利性并提高材料利用效率。

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引用次数: 0

Fire behaviour of pin-ended concrete-encased concrete-filled steel tube (CECFST) slender columns under concentric and eccentric compression

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120067

Nuoxin Wu, Gaoming Zhu, Kang Hai Tan

Concrete-encased concrete-filled steel tube (CECFST) columns are widely recognised for their superior structural performance in mega construction structures. Despite extensive research under normal conditions, limited attention has been given to their performance in fire conditions. In this study, five CECFST slender columns were tested under transient fire conditions to investigate their fire behaviour. Key test findings included the failure mode, temperature distribution, structural response and fire resistance. Experimental results revealed that fire-exposed CECFST columns generally showed global buckling accompanied by extensive tensile cracking, demonstrating excellent ductility. Explosive spalling was observed in two specimens despite adding 0.2 vol% PP fibres. Moreover, compared to conventional concrete-filled steel tube (CFST) columns, CECFST columns exhibited superior fire resistance, highlighting their effectiveness as a ductile structural member under fire exposure. In addition, a calculation model was developed based on finite difference method (FDM) to predict the temperature distribution and strength reduction for CECFST columns in fire conditions. The calculation model can be easily implemented via MATLAB, and the code is open source. The proposed model was verified with test results, showing reasonable accuracy. This study provides insights and practical tool for evaluating fire performance of CECFST columns, particularly in super high-rise buildings and infrastructure projects where the maximum fire resistance may be required by the code.

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引用次数: 0

Inverse design of performance-oriented cellular metamaterials

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120048

Haojie Huang, Shuang Zhang, Yongquan Li

Origami-inspired structures have driven the development of metamaterials with specialized mechanical performance. Although several design methods exist for origami metamaterials, performance-oriented inverse design remains to be accomplished. This study introduces a performance-oriented inverse design method for constructing cellular metamaterials. First, a novel thick-panel origami structure is proposed and modified, which is demonstrated to have a single degree-of-freedom using screw theory. Subsequently, the topological geometry of the improved structure is analyzed, revealing a negative Poisson’s ratio. Leveraging this property, a class of metamaterial cells and their corresponding cellular metamaterials are inverse-designed, with the thick-panel origami regarded as a rectangular block. This performance-oriented inverse design approach provides a novel perspective for constructing cellular metamaterials.

引用次数: 0

Understanding the impact of spiral reinforcement on GFRP-RC beams under combined shear and torsion loading

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120019

Mohammed Gamal Gouda , Ibrahim T. Mostafa , Hamdy M. Mohamed , Alaa Sherif , Mohamed H. Agamy

To date, the combined shear and torsional behavior of reinforced concrete (RC) beams reinforced with continuous glass-fiber reinforced polymer (GFRP) spiral stirrups has not been thoroughly investigated. Accordingly, this paper investigates the behavior of RC beams reinforced with GFRP bars and rectangular continuous spirals under combined shear and torsion. The experimental program involved testing six RC beams, each measuring 3000 mm in length, 200 mm in width, and 400 mm in depth. The test parameters focused on the configuration of transverse reinforcement (GFRP spirals versus GFRP tie stirrups) and varying transverse reinforcement ratios. Four specimens were reinforced with GFRP spirals at different reinforcement ratios to assess the effect of transverse reinforcement on shear and torsional capacities. One specimen was reinforced with GFRP tie stirrups to investigate the influence of stirrup configuration, and one specimen was without web reinforcement (control) to evaluate the impact of concrete strength on the capacities. Experimental results showed that beams with GFRP spirals or tie stirrups failed due to the progressive widening of diagonal tension cracks and subsequent rupture of the GFRP reinforcement at bent portions, while the control beam failed due to concrete splitting. The results demonstrated that reducing the spacing of GFRP spirals significantly enhanced shear and torsional capacities. The experimental findings were compared with existing design codes and a newly proposed model based on the space truss analogy.

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引用次数: 0

Rope effect in mechanical panel-timber connections: A comparison between screws and dowels

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120036

Mattia Debertolis , Yue Wang , Tianxiang Wang , Roberto Crocetti , Magnus Wålinder

Previous studies have demonstrated the potential of birch plywood as a substitute for steel plates in multi-plane shear connections of timber structures due to, among other things, its low environmental impact, better workability, and relatively low cost. However, models in modern building codes, such as Eurocode EN1995–1 (EC5), can be used to determine the load-carrying capacity of timber connections with up to two shear planes. Furthermore, some studies have shown that EC5 design model tend to underestimate the actual load-carrying capacity of timber connections. Therefore, there are some uncertainties concerning suitable design models to assess the load-carrying capacity of such connections. This study was preliminary conducted to shed light on the reasons for such discrepancies, conducting several experiments on both doweled and screwed birch plywood-to-timber connections, with either two or four shear planes. The analytical load-carrying capacities estimated by EC5 showed underestimation of the experimental results, with greater underestimation when fully threaded screws are adopted as fasteners, rather than smooth dowels. Furthermore, regardless of the type of fastener, a substantial discrepancy between EC5’s prediction and experimental results was observed when the number of shear planes was increased from two to four. The results of the investigations indicate that the main cause of the discrepancies might be associated with the so-called “rope effect” which is taken into account by EC5’s design approach in an over-conservative manner.

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引用次数: 0

Generative design of hierarchical truss structures with desired stiffness and strength: Recursive multiscale topology optimization based on powder bed fusion

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-11 DOI: 10.1016/j.engstruct.2025.120016

Yizhuo Liu , Hao Hua , Zijian Jia , Ludger Hovestadt

The stiffness and strength of uniaxial compressive material can be equivalently realized by a hierarchical truss structure. This work fills the conceptual gap between weight minimization of single truss and the design of hierarchical truss metamaterial, resulting in the formulation of heterogeneous non-periodic structures. Multiscale topology optimization integrated with additive manufacturing (AM) leads to disruptive innovation in construction. The structural hierarchy plays a pivotal role in the creation of bulk material properties. Therefore, a systematic understanding of the cross-level behavior is critical. A rod with the desired stiffness and strength is implemented with an optimized truss with equivalent mechanical properties while using less material. Euler’s critical problem is transformed into the global buckling problem of the truss at the lower level of hierarchy. The recursive algorithm constructs and simultaneously searches for the best structure of multi-level hierarchy. A series of uniaxial compression tests compared the differences between the theoretical model and the specimens produced by powder bed fusion (PBF). The truss joint geometry for PBF was tuned to approximate the stiffness and stability predicated by the mathematical model. Despite the AM imperfection, the statistical mechanical properties are consistent across specimens. 3D-printed trusses can be assembled by welding or bolting connections into larger structures in practice. Compared with solid material with equivalent stiffness and strength, the hierarchical fusiform trusses save significant amounts of material. The cross-level map between the mechanical behavior from neighboring levels of hierarchy facilitates the estimation of the upper bound of the levels of hierarchy.

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引用次数: 0

Unified tri-linear theoretical model for masonry infilled RC frames subjected to out-of-plane lateral loads

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-10 DOI: 10.1016/j.engstruct.2025.120039

Xinyao Xie , Zi-Xiong Guo , Syed Humayun Basha

The out-of-plane (OOP) behavior of infill walls has received minimal attention in the past due to the lack of reliable analytical solutions. To solve this issue, the research article proposed a simplified tri-linear theoretical model to comprehend the OOP behavior of masonry infills considering different performance levels (cracking, peak, and ultimate). This study was mainly categorized into four main parts. Firstly, it involved determining the OOP deflection field and arching mechanism of masonry infills through the advanced digital image correlation technique to form a solid foundation for theoretical investigations. Secondly, the principle of mechanics was employed to derive the OOP cracking load and the corresponding deflection. Thirdly, the OOP peak load capacity was calculated by applying the principle of minimum potential energy and considering material constitutive laws. Finally, geometrical calculations were utilized to determine the peak and ultimate deflections, making it a comprehensive and rigorous study. Upon analyzing the DIC deflection field, it was observed that the RC frame surrounding the infills effectively constrained their deflections along the boundary edges. This indicated that the assumption of hinge supports as boundary conditions were reasonable. Theoretical investigations revealed that the peak load capacity of the wall was significantly influenced by the contact length between segments in the OOP direction, which was roughly 44.8 % of the wall thickness at the peak point. Additionally, the OOP deflection after cracking depended on the wall's slenderness ratio, height, peak compressive strain, and crushing strain. It was found that the developed theoretical tri-linear model fairly predicted the OOP performance of infills (slenderness ratios range from 8.42 to 28.81) with less error in comparison to the previously developed theoretical models.

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引用次数: 0

Axial compressive behavior and stress-strain model analysis of FRP-confined corroded RC columns with different-sized circular sections

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-10 DOI: 10.1016/j.engstruct.2025.120025

Fang Yuan , Haoran Li , Wenbin Liu , Huihui Li , Jinlong Pan

Compared to the non-corroded counterparts, very few studies have focused on the size effect on the mechanical performance and stress-strain behavior of FRP-confined corroded RC columns. To fill this research gap, this paper experimentally studied the axial compressive behavior and stress-strain response of several CFRP-confined corroded RC columns with different-sized circular sections. 96 circular RC columns were designed and the critical test parameters mainly included the column size, corrosion rate, and the number of CFRP layers. Subsequently, the effects of corrosion rate, the number of CFRP layers, and size effect on the failure modes, load-displacement curves, stress-strain curves, ultimate conditions, and FRP confining efficiency of the specimens were extensively examined. The results indicated that there was no significant size effect on the stress-strain behavior of FRP-confined corroded concrete (i.e., the damaged concrete due to rebar corrosion), but it would be more pronounced when the specimen size was small and the columns were under higher corrosion rates. In addition, by incorporating the influence of rebar corrosion on the damage of concrete and FRP confining efficiency, this study proposed the improved stress-strain models for FRP-confined corroded concrete and the analytical ultimate axial load model for the FRP-confined corroded RC columns. It is observed that the proposed models could yield better prediction results than the existing models available in the literature.

{"title":"Axial compressive behavior and stress-strain model analysis of FRP-confined corroded RC columns with different-sized circular sections","authors":"Fang Yuan , Haoran Li , Wenbin Liu , Huihui Li , Jinlong Pan","doi":"10.1016/j.engstruct.2025.120025","DOIUrl":"10.1016/j.engstruct.2025.120025","url":null,"abstract":"<div><div>Compared to the non-corroded counterparts, very few studies have focused on the size effect on the mechanical performance and stress-strain behavior of FRP-confined corroded RC columns. To fill this research gap, this paper experimentally studied the axial compressive behavior and stress-strain response of several CFRP-confined corroded RC columns with different-sized circular sections. 96 circular RC columns were designed and the critical test parameters mainly included the column size, corrosion rate, and the number of CFRP layers. Subsequently, the effects of corrosion rate, the number of CFRP layers, and size effect on the failure modes, load-displacement curves, stress-strain curves, ultimate conditions, and FRP confining efficiency of the specimens were extensively examined. The results indicated that there was no significant size effect on the stress-strain behavior of FRP-confined corroded concrete (i.e., the damaged concrete due to rebar corrosion), but it would be more pronounced when the specimen size was small and the columns were under higher corrosion rates. In addition, by incorporating the influence of rebar corrosion on the damage of concrete and FRP confining efficiency, this study proposed the improved stress-strain models for FRP-confined corroded concrete and the analytical ultimate axial load model for the FRP-confined corroded RC columns. It is observed that the proposed models could yield better prediction results than the existing models available in the literature.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120025"},"PeriodicalIF":5.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Design and analysis of a novel star-shaped auxetic cylindrical metamaterial with excellent mechanical performance

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-10 DOI: 10.1016/j.engstruct.2025.120047

Bai-Xuan Song, Jian-Gang Guo, Chuan Qu, Zhi-Yong Wang

This paper introduces a novel auxetic cylindrical metamaterial based on a plate structure with a star-shaped cellular design. This design aims to achieve outstanding negative Poisson's ratio (NPR) characteristics and enhance mechanical performance. Compared with traditional beam-based lattice structures, the auxetic cylinder, leveraging its star-shaped structure, shows remarkable mechanical improvements. The research details the entire process from the design to manufacturing of these auxetic metamaterials. A significant feature is their ability to contract radially under axial compression, which gives them excellent energy absorption and mechanical resilience. The finite element method (FEM) is employed to analyze the impact of various design parameters, such as angles, ligament lengths, wall thicknesses, and internal diameters. By comparing simulation results with experimental data, the reliability and robustness of the FEM model are verified. This study provides valuable references for the design of advanced metamaterials with adjustable mechanical properties. It also reveals great potential for applications in numerous fields, including aerospace, biomedical devices, and protective equipment, etc.

{"title":"Design and analysis of a novel star-shaped auxetic cylindrical metamaterial with excellent mechanical performance","authors":"Bai-Xuan Song, Jian-Gang Guo, Chuan Qu, Zhi-Yong Wang","doi":"10.1016/j.engstruct.2025.120047","DOIUrl":"10.1016/j.engstruct.2025.120047","url":null,"abstract":"<div><div>This paper introduces a novel auxetic cylindrical metamaterial based on a plate structure with a star-shaped cellular design. This design aims to achieve outstanding negative Poisson's ratio (NPR) characteristics and enhance mechanical performance. Compared with traditional beam-based lattice structures, the auxetic cylinder, leveraging its star-shaped structure, shows remarkable mechanical improvements. The research details the entire process from the design to manufacturing of these auxetic metamaterials. A significant feature is their ability to contract radially under axial compression, which gives them excellent energy absorption and mechanical resilience. The finite element method (FEM) is employed to analyze the impact of various design parameters, such as angles, ligament lengths, wall thicknesses, and internal diameters. By comparing simulation results with experimental data, the reliability and robustness of the FEM model are verified. This study provides valuable references for the design of advanced metamaterials with adjustable mechanical properties. It also reveals great potential for applications in numerous fields, including aerospace, biomedical devices, and protective equipment, etc.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120047"},"PeriodicalIF":5.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Reinforced concrete beam full response prediction with hybrid feature-orientation transformer-LSTM model

IF 5.6 1区工程技术 Q1 ENGINEERING, CIVIL

Engineering Structures

Pub Date : 2025-03-10 DOI: 10.1016/j.engstruct.2025.120040

Zecheng Yu, Bing Li

Accurate and efficient prediction of load-displacement behavior in reinforced concrete (RC) beams is essential for data-driven interventions and predictive maintenance in structural engineering. Such predictions are critical for ensuring the safety, reliability, and longevity of structures. Develop a comprehensive approach that incorporates advanced deep learning (DL) techniques, leveraging historical data and time series modeling to achieve high-precision predictions. This study introduces a hybrid feature-orientation Transformer-LSTM (HFT-LSTM) model for accurately predicting the load-displacement response of RC beams, from initial loading to failure. It leverages a Transformer architecture, embedded with a multi-headed attention mechanism, to achieve a deeper representation of constant features and dynamic fusion of variable features, enabling a more comprehensive understanding of the RC beam's behavior. It employs a bidirectional LSTM to capture dynamic and temporal relationships within the displacement series. To gain a deeper understanding of the history-dependent mechanical behavior of RC beams, we conducted a detailed analysis of the influence of input features on the load-displacement curve. The proposed model significantly outperforms existing DL models, achieving a 46 % reduction in Mean Absolute Error (MAE), a 58 % decrease in Root Mean Squared Error (RMSE), a 5 % increase in R-squared (R²) and Explained Variance (EV), and a 36 % reduction in Median Absolute Error (MedAE).

{"title":"Reinforced concrete beam full response prediction with hybrid feature-orientation transformer-LSTM model","authors":"Zecheng Yu, Bing Li","doi":"10.1016/j.engstruct.2025.120040","DOIUrl":"10.1016/j.engstruct.2025.120040","url":null,"abstract":"<div><div>Accurate and efficient prediction of load-displacement behavior in reinforced concrete (RC) beams is essential for data-driven interventions and predictive maintenance in structural engineering. Such predictions are critical for ensuring the safety, reliability, and longevity of structures. Develop a comprehensive approach that incorporates advanced deep learning (DL) techniques, leveraging historical data and time series modeling to achieve high-precision predictions. This study introduces a hybrid feature-orientation Transformer-LSTM (HFT-LSTM) model for accurately predicting the load-displacement response of RC beams, from initial loading to failure. It leverages a Transformer architecture, embedded with a multi-headed attention mechanism, to achieve a deeper representation of constant features and dynamic fusion of variable features, enabling a more comprehensive understanding of the RC beam's behavior. It employs a bidirectional LSTM to capture dynamic and temporal relationships within the displacement series. To gain a deeper understanding of the history-dependent mechanical behavior of RC beams, we conducted a detailed analysis of the influence of input features on the load-displacement curve. The proposed model significantly outperforms existing DL models, achieving a 46 % reduction in Mean Absolute Error (MAE), a 58 % decrease in Root Mean Squared Error (RMSE), a 5 % increase in R-squared (R²) and Explained Variance (EV), and a 36 % reduction in Median Absolute Error (MedAE).</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120040"},"PeriodicalIF":5.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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