Structures最新文献

{"title":"Numerical study on seismic performance of a prefabricated subway station considering the influence of construction process","authors":"","doi":"10.1016/j.istruc.2024.107218","DOIUrl":"10.1016/j.istruc.2024.107218","url":null,"abstract":"<div><p>In previous seismic analyses of cast-in-place stations, the importance of the construction process was typically not emphasized. Unlike cast-in-place stations, prefabricated subway stations feature innovative construction methods. The effect of ignoring the complete construction process on the seismic performance of prefabricated subway stations remains unclear, and this study aims to address this issue. In this research, a three-dimensional nonlinear numerical model considering soil-structure interaction (SSI) was established. First, the complete construction process of the station, including excavation of the foundation pit and structural assembly, was replicated. The initial state before dynamic loading was clearly defined. Subsequently, the seismic response mechanisms of the station, including deformation, SSI, acceleration, and internal forces, were thoroughly investigated, revealing the impact of structural type and construction method on seismic performance. The results indicate that neglecting the complete construction process leads to differences in the initial state before dynamic loading, resulting in variations in seismic response. Specifically, ignoring the assembly process causes an average bending moment error of 59 % and an axial force error of 35 % for each component. By comprehensively analyzing these findings, a deeper understanding of the intricate interplay between assembly techniques, structural behavior, and construction processes in seismic contexts can be attained, thereby informing more robust engineering practices.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142233617","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}

{"title":"Enhancing seismic performance of structures: A comprehensive review of hybrid passive energy dissipation devices","authors":"","doi":"10.1016/j.istruc.2024.107223","DOIUrl":"10.1016/j.istruc.2024.107223","url":null,"abstract":"<div><p>When an earthquake occurs, a substantial amount of elastic strain energy is released, and its intensity is typically measured by Peak Ground Acceleration (PGA). Installing dampers in buildings is a recognized method for dissipating this energy. Passive energy dissipation devices perform effectively under both high and low PGA conditions. Hybrid dampers combine two or more devices into a single unit and are designed to overcome individual weaknesses and enhance overall strength. This study provides a comprehensive review of hybrid passive energy-dissipating devices, emphasizing their crucial role in enhancing the seismic performance of structures. Hybrid dampers are instrumental in reducing roof displacement, drift, inter-story movement, floor acceleration, and base shear, thus significantly improving seismic resilience. The review also outlines various types of devices that are combined to create hybrid dampers, highlighting their importance in ongoing research. Despite numerous numerical analyses and experimental tests, research into implementing hybrid dampers in concrete structures remains limited. Consequently, there is a significant opportunity for improvement, design, development, and implementation of hybrid damping devices in buildings. These devices offer superior vibration control characteristics, making them an attractive option for enhancing the overall structural stability of structures.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232751","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}

{"title":"Deflection estimation of reinforced concrete beams using long-gauge optic sensors","authors":"","doi":"10.1016/j.istruc.2024.107249","DOIUrl":"10.1016/j.istruc.2024.107249","url":null,"abstract":"<div><p>Deflection is a crucial indicator in structural health monitoring, directly impacting the service life, safety, and economic viability of structures. However, current indirect methods for measuring deflection, such as multi-element FBG sensors or accelerometers, often have limitations. While they may be suitable for flexure-dominated reinforced concrete (RC) specimens in the elastic stage, they neglect the significant influence of nonlinearity and shear deformation. This paper introduces a new approach for estimating the deflection of reinforced concrete (RC) beams using distributed long-gauge optic sensors. The method tackles the limitations of current methods by incorporating the crucial factors of shear deformation, neutral axis position variation and shear stiffness degradation. Experimental studies are first conducted to validate the accuracy and stability of long-gauge optic sensors in small-scale RC members. Algorithms are then utilized the measurement data to estimate the deflection. The results demonstrate the excellent performance of long-gauge optic sensors in measuring shear deformation and vertical deflection of RC beams, as evidenced by comparisons with LVDT measurements. Additionally, a method for decoupling flexural and shear deformation is proposed. This method offers a preliminary assessment of the reinforced concrete (RC) beam type by quantifying the relative significance of shear deformation.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232709","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}

{"title":"Investigation of interfacial bond strength of circular CFST columns based on ordinary and inorganic polymers through advanced machine learning methods","authors":"","doi":"10.1016/j.istruc.2024.107252","DOIUrl":"10.1016/j.istruc.2024.107252","url":null,"abstract":"<div><p>Concrete-filled steel tube (CFST) is a combination of materials, in which the interfacial bond-slip behavior is the prerequisite to reflect the synergistic loading of external steel tube and core concrete. The inorganic polymer concrete within the concrete-filled steel tube (IPCFST) compensates for the drying shrinkage of the concrete and enhances the adhesion at the interface between the steel tube and the concrete. However, the current code is too simple for the bond strength of CFSTs, and the existing theoretical calculation methods are not universally applicable. This paper aims to develop a practical artificial neural network tool for predicting the interfacial bond strength of ordinary CFSTs and IPCFSTs. An efficient prediction model for the bond strength of CFST interfaces was developed using a radial basis function network (RBFNN), with concrete strength, steel tube size, bond length and other factors as the main parameters. Bond performance test data was collected for a sample database of 322 circular CFST columns, including 56 ordinary CFSTs and 263 IPCFSTs. The results show that the Artificial Neural Network (ANN) algorithm can effectively address the bond strength problem of CFST structures and improve the accuracy and density of prediction in the comparative analyses with the measured values and the results of the semi-theoretical formulations. Based on the prediction results of ANN model, a sensitivity analysis of the parameters using Garson's algorithm shows that the diameter-to-thickness ratio and concrete strength significantly affect bond strength for both ordinary CFSTs and IPCFSTs. This study provides a more reliable prediction method and technical support for the engineering design of CFST structures.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230483","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}

{"title":"An efficient isogeometric buckling optimization framework for multi-patch laminated shells: Leveraging 3D solid elements, lamination parameters and penalty method","authors":"","doi":"10.1016/j.istruc.2024.107212","DOIUrl":"10.1016/j.istruc.2024.107212","url":null,"abstract":"<div><p>Buckling is a common failure mode of laminated shell structures during service, and isogeometric analysis methods are highly suitable for the buckling analysis due to their accurate geometric modeling capability and high-order continuity. However, the isogeometric buckling analysis for a multi-patch structure and its optimal design still face challenges in computational efficiency. To address this issue, this paper proposes an integrated framework for the buckling optimization of multi-patch laminated shells, which leverages 3D solid elements, lamination parameters, and the penalty coupling method. Solid-shell elements have advantages in shell analysis due to their simplicity, absence of rotational degrees of freedom, and adaptive layering in the thickness direction. Lamination parameters simplify the optimization of fiber orientations in laminated shells by condensing the design variable space and improving the convexity of the optimization problem. The penalty method can handle the coupling in multiple patches at a relatively low cost. Nevertheless, lamination parameters are rarely applied to the case of solid-shell elements. In addition, despite using lamination parameters, the number of design variables for multi-patch structures remains significantly large. To tackle these issues, this study derives the solid-shell formulation in lamination parameters and the sensitivity analysis formulae in the reverse mode. Experiment validation is conducted to assess the accuracy of the proposed method based on lamination parameters with solid elements, the feasibility of the multi-patch optimization model, and the computational efficiency of optimization sensitivity based on the reverse mode compared to the forward counterpart common in the literature.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230482","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}

{"title":"Effect of horizontal web reinforcement, depth, proportionated loading and bearing plates on shear strength and serviceability of reinforced concrete deep beams","authors":"","doi":"10.1016/j.istruc.2024.107106","DOIUrl":"10.1016/j.istruc.2024.107106","url":null,"abstract":"<div><p>In this paper, the strength, serviceability and failure modes of eleven reinforced concrete (RC) deep beams were evaluated. The small, medium and large-size specimens with heights ranging from 300 to 1250 mm and effective spans from 600 to 2500 mm were tested up to failure under the three-point bending test. The length of loading and bearing plates varied from 100 to 400 mm, and the percentage of horizontal web reinforcement varied between 0.00 % and 0.45 %. Test results revealed that distributed web reinforcement and proportionate loading and supporting plates mitigate the size effect. Further, when the percentage of horizontal shear reinforcement increased, the mode of failure changed from diagonal tension to shear compression. From the test results, it has been concluded that the optimum horizontal web reinforcement was 0.25 % for achieving the highest ultimate and service load. The strength reduction factor of maximum shear force expression of ACI 318–19 [25] code adequate even in the case of deep beams failing in shear compression mode is experimentally validated.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232708","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}

{"title":"Analysis of concrete damage at anchorage end of the high-speed railway bridge sound barrier under the 400 km/h train-induced wind loads","authors":"","doi":"10.1016/j.istruc.2024.107284","DOIUrl":"10.1016/j.istruc.2024.107284","url":null,"abstract":"<div><p>The sound barrier installed on high-speed railway bridges withstands repeated train-induced wind load, which may lead to concrete damage at its anchorage end. This paper focuses on the assessment of concrete static damage at the sound barrier anchorage end under train-induced wind loads. The nonlinear finite element model of the sound barrier anchorage system is established to analyze the stress distribution, strain distribution and static damage of concrete structure at the anchorage end under 400 km/h train-induced wind loads in respect of different bolt preloads. The simulated results illustrate that both mortar and concrete near bolt holes suffer a certain degree of tensile and compressive damage. The maximum tensile and compressive damage factor values for mortar and concrete are 0.930, 0.643 and 0.892, 0.434 respectively. In addition, the effects of train-induced wind load on the internal force of the sound barrier anchorage take nearly no account, with a maximum of only 0.68 %. The results indicate that bolt preload is the most significant factor for concrete static damage, while the train-induced wind load appears negligible. An appropriate bolt preload can avoid the concrete static damage of the sound barrier anchorage end, and guarantee the structural stability of the sound barrier.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232752","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}

{"title":"Hybrid simulation testing of two-storey low-aspect-ratio nuclear RC shear walls with normal- and high-strength reinforcement: Seismic performance evaluation and economic assessment","authors":"","doi":"10.1016/j.istruc.2024.107200","DOIUrl":"10.1016/j.istruc.2024.107200","url":null,"abstract":"<div><p>Low-aspect-ratio reinforced concrete (RC) shear walls have been commonly used in several nuclear facilities in containment and safety-related structures. Despite being a potential alternative to reduce rebar congestion and subsequently minimize complex construction activities typically associated with nuclear facilities, there has been limited experimental research on investigating the impact of using high-strength reinforcement (HSR) on the seismic performance of such walls, particularly in a multi-storey context. This lack of research is mainly due to considerable challenges imposed when testing such multi-storey nuclear RC shear walls in most laboratories. Therefore, the current study presents the experimental results of two two-storey low-aspect-ratio nuclear RC shear walls that were tested utilizing the seismic hybrid simulation testing technique. In this respect, walls W1-NSR and W2-HSR were designed using normal-strength reinforcement (NSR) and HSR, respectively, where the two test walls had comparable capacities to allow for direct comparisons. Both walls were subjected to various ground motion levels, spanning from operational to design and beyond-design earthquake scenarios. The experimental findings are then presented to include the force-displacement responses, the multi-storey effects, ductility capacities, lateral and rotational stiffnesses, rebar strains, and cracking patterns of the test walls. Subsequently, an economic assessment was carried out to quantify the total rebar weights and the corresponding construction costs of such walls. In addition, the expected seismic repair costs were determined based on a three-dimensional digital image correlation technique that provided information on the damage states of the test walls under different earthquake levels. The results show that although W1-NSR and W2-HSR attained similar force and moment capacities, W2-HSR achieved a relatively higher ductility capacity than W1-NSR. However, larger cracks were observed in W2-HSR compared to W1-NSR, which was attributed to the associated larger rebar spacing in the former relative to the latter. The economic assessment results demonstrate that using HSR minimized the rebar weights and construction costs, while both walls had similar seismic repair costs at their design and beyond-design earthquake levels. Both the seismic performance and economic assessment results presented in the current study are expected to aid future editions of relevant design standards in adopting HSR in nuclear construction practice.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352012424013523/pdfft?md5=72cc558fc583d15a3d41f7328089c483&pid=1-s2.0-S2352012424013523-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction and optimization of surface waviness of WAAM components using a hybrid Rank-Gaussian PSO algorithm and ANN","authors":"","doi":"10.1016/j.istruc.2024.107247","DOIUrl":"10.1016/j.istruc.2024.107247","url":null,"abstract":"<div><p>Surface waviness is crucial for the quality of components produced via the wire and arc additive manufacturing (WAAM) process. This study presents a novel method for predicting surface waviness, employing an advanced model to optimize process parameter configurations using a combination of Rank-Gaussian particle swarm optimization (RGPSO) and an Artificial Neural Network (ANN). The novelty of this process is that the RGPSO not only optimizes the hyperparameters of the ANN model to enhance prediction performance, but also addresses surface waviness optimization. The RGPSO algorithm's optimization performance is evaluated using 23 benchmark functions, demonstrating competitiveness against nine comparative meta-heuristic algorithms. Experimental data on surface waviness from the literature are utilized to train, test and validate three different prediction models, including a standalone ANN model, a PSO optimized ANN (PSO-ANN) model, and an RGPSO optimized ANN (RGPSO-ANN) model. The results indicate that the developed RGPSO-ANN model achieves the highest accuracy in terms of the metrics <span><math><mi>RMSE</mi></math></span> (0.019), <span><math><mi>R</mi></math></span> (0.996), <span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mrow><mfenced><mrow><mn>0.990</mn></mrow></mfenced></mrow><mo>,</mo><mspace></mspace><mi>MAE</mi></mrow></math></span> (0.013), <span><math><mrow><mi>RMSLE</mi><mrow><mfenced><mrow><mn>0.013</mn></mrow></mfenced></mrow><mo>,</mo><mspace></mspace></mrow></math></span>and <span><math><mi>MAPE</mi></math></span> (3.46 %). It performs better than the PSO-ANN model (<span><math><mi>RMSE</mi></math></span> 0.026, <span><math><mi>R</mi></math></span> 0.975, <span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>0.982</mn><mo>,</mo></mrow></math></span> <span><math><mi>MAE</mi></math></span> 0.019, <span><math><mrow><mi>RMSLE</mi><mspace></mspace></mrow></math></span>0.019<span><math><mrow><mo>,</mo><mi>a</mi></mrow></math></span>nd <span><math><mi>MAPE</mi></math></span> 5.73 %), and better than the ANN (<span><math><mi>RMSE</mi></math></span> 0.046, <span><math><mrow><mi>R</mi><mspace></mspace></mrow></math></span>0.991, <span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mspace></mspace><mn>0.944</mn><mo>,</mo></mrow></math></span> <span><math><mi>MAE</mi></math></span> 0.034, <span><math><mrow><mi>RMSLE</mi><mn>0.032</mn></mrow></math></span> and <span><math><mi>MAPE</mi></math></span> 9.31 %). The RGPSO, PSO and other optimization algorithms are then applied to minimize the surface waviness of a WAAM component. RGPSO achieved the optimal value (0.1631 mm), which corresponds to a 12.6 % reduction compared to the best value obtained using PSO.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232707","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}

{"title":"Experimental investigation of heat-damaged reinforced concrete columns strengthened with different schemes","authors":"","doi":"10.1016/j.istruc.2024.107282","DOIUrl":"10.1016/j.istruc.2024.107282","url":null,"abstract":"<div><p>This paper experimentally investigates the efficacy of two jacketing techniques in the rehabilitation of square and circular reinforced concrete (RC) columns that were exposed to highly elevated temperatures. Twenty-four RC columns were tested under an axial compression load, which was divided into three groups. The first group consisted of the control specimens without applying any strengthening approach. Group 2 consisted of the columns with the strengthening configuration of near-surface-mounted (NSM) rebars and carbon fiber-reinforced polymer (CFRP) layers. Regarding the third group, columns were strengthened using two layers of welded-wire mesh (WWM) and ultra-high-performance fiber concrete (UHPFC) jacketing. Four columns from each group were subjected to an elevated temperature of 600 °C for a duration of 3 h, while the remaining half were subjected to room temperature. The results showed that after three hours at a temperature of 600 °C, both strengthening schemes successfully restored and exceeded the initial load-carrying capability of all columns. Utilizing WWM with UHPFC jacketing as new strengthening technique proved to be the most efficient method for reinstating the load-carrying capability of circular columns (+321.8 %) and square columns (+140.6 %) that were subjected to high temperatures. Additionally, an analytical model was proposed to estimate the ultimate load capacity of RC columns after rehabilitation.</p></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173053","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}