Structures最新文献

{"title":"Nonlinear transient deflections of multi-layer sector plate structures on auxetic concrete foundation: Introducing an artificial intelligence algorithm for nonlinear problems","authors":"Peixi Guo ,&nbsp;Yao Zhang ,&nbsp;Yu Xi ,&nbsp;Kashif Saleem ,&nbsp;Mohammed El-Meligy ,&nbsp;Hamed Safarpour","doi":"10.1016/j.istruc.2024.107563","DOIUrl":"10.1016/j.istruc.2024.107563","url":null,"abstract":"<div><div>This paper presents a comprehensive study on the nonlinear transient deflections of multi-layer sector plates, with a focus on presenting an artificial intelligence algorithm for addressing nonlinear problems in structural mechanics using the datasets of mathematical simulation. Multi-layer sector plates, commonly used in various engineering applications, exhibit complex nonlinear behaviors under external loading, particularly when coupled with unconventional materials such as auxetic concrete foundations. In this study, we propose the use of a mathematical simulation to analyze the nonlinear transient deflections of multi-layer sector plates on an auxetic concrete foundation. After that, a dataset (approximately 3750 data) is obtained and the algorithm is trained to capture the intricate nonlinear responses of the structure under different loading conditions. By leveraging an artificial intelligence algorithm, the algorithm can accurately predict the nonlinear behaviors of the multi-layer sector plate system, including vibration characteristics, dynamic response, and stability analysis. Through extensive numerical and validation studies, we demonstrate the effectiveness of the current mathematical modeling in accurately capturing the nonlinear transient deflections of multi-layer sector plates on auxetic concrete foundations. Furthermore, the proposed machine learning algorithm offers a promising approach for addressing nonlinear problems in structural mechanics, providing a versatile and efficient tool for engineers to analyze and optimize complex structural systems. By integrating machine learning techniques into structural analysis, researchers can enhance the accuracy and efficiency of nonlinear transient deflection studies, paving the way for advancements in structural engineering and related fields.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107563"},"PeriodicalIF":3.9,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538662","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 human-induced vibration response and TLD vibration reduction of high fundamental frequency aluminum alloy footbridge","authors":"Chunling Lu ,&nbsp;Jiahui Xia ,&nbsp;Xiangxiang Wang ,&nbsp;Kang Wen ,&nbsp;Qiang Wang ,&nbsp;Qizhou Liu","doi":"10.1016/j.istruc.2024.107579","DOIUrl":"10.1016/j.istruc.2024.107579","url":null,"abstract":"<div><div>To investigate the variation laws of human-induced vibration responses coupled with high-frequency footbridges and explore the feasibility of Tuned Liquid Damper (TLD) for vibration reduction in high fundamental frequency footbridges. Field tests were carried out on an aluminum footbridge (with a vertical fundamental frequency of 7.42 Hz) to assess the impact of different walking patterns on human-structure interaction and to evaluate the applicability of various theoretical models for high-frequency aluminum footbridges. The effectiveness of a simple pure water TLD on the vibration control was tested, and the feasibility of using a high-viscosity fluid for vibration control was analyzed. Results indicate that an increase in both the number of pedestrians and walking frequency enhances structural response. The Distributed-Mass-Stiffness-Damping (D-MSD) model effectively captures the dynamic coupling characteristics between humans and the structure. The introduction of the TLD device lowers the system's fundamental frequency and increases the damping ratio, with optimal damping force observed when the TLD's fundamental frequency is close to the bridge's lateral fundamental frequency, achieving a maximum vibration reduction rate of 34 %. While using a high-viscosity fluid increases fluid damping force, the effectiveness of vibration control may still be debatable due to insignificant differences in stiffness calculated by the equivalent Nonlinear Stiffness and Damping (NSD) model. The findings provide relevant data for structural health monitoring and vibration control of high fundamental frequency footbridges with similar structural systems under human-induced vibration excitation.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107579"},"PeriodicalIF":3.9,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538730","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":"Seismic isolation strategy via controlled soft first story with innovative multi-stage yielding damper: Experimental and numerical insights","authors":"Sobhan Ghasemi ,&nbsp;Mahmood Hosseini ,&nbsp;Shuling Hu ,&nbsp;Amir Shahram","doi":"10.1016/j.istruc.2024.107553","DOIUrl":"10.1016/j.istruc.2024.107553","url":null,"abstract":"<div><div>While the presence of a soft story within a building is typically discouraged in structural engineering due to potential vulnerabilities, this research proposes a strategy that incorporates seismic isolation concepts by integrating a soft first story within the structural framework. This approach challenges traditional reluctance by demonstrating the potential benefits of such a configuration. The primary objectives are twofold: firstly, to diminish seismic responses and enhance structural resilience when subjected to earthquake forces, and secondly, to reduce construction costs as compared to conventional passive control methods. The seismic responses assessed and compared in this study encompass story displacements, story drifts, floor accelerations and base shear of the structure. Furthermore, an investigation is conducted into a replaceable or repairable shear fuse that serves as a controller in the Controlled Soft First Story (CSFS) strategy, namely, an innovative Multi-stage Steel Yielding Damper (MSYD). Notably, the numerical analysis of the introduced damper has been carried out, followed by rigorous validation testing under experimental conditions. This study elucidates the implementation of this strategy within the structural framework. The overarching principle behind employing the CSFS results in outcomes akin to those achieved with base isolation techniques. However, it distinguishes itself by significantly mitigating the construction costs around 70% associated with this system when juxtaposed with traditional base isolation systems.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107553"},"PeriodicalIF":3.9,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538822","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":"Effects of reservoir-bottom explosion on concrete gravity dam and potential mitigation measure","authors":"Yong Fan ,&nbsp;Guangdong Yang ,&nbsp;Wenzhuo Li ,&nbsp;Zhenyu Feng ,&nbsp;Pengchang Sun ,&nbsp;Bin Tian","doi":"10.1016/j.istruc.2024.107514","DOIUrl":"10.1016/j.istruc.2024.107514","url":null,"abstract":"<div><div>As an essential infrastructure, dams may suffer explosive loads during their lifecycle. To reveal the dynamic response characteristics of concrete gravity dam (CGD) under reservoir-bottom explosions and explore potential mitigation measures, a 1:100 concrete gravity dam model was poured, and eight test scenarios under different explosion distances, water depths and detonation depths were designed. The time-history curves of water pressure, acceleration, and velocity under different test scenarios were recorded and compared to better understand the dynamic response of CGD under reservoir-bottom explosions. In addition, bubble curtains were used as a potential measure to mitigate the effects of underwater explosions on CGD. The results indicate that the maximum peak acceleration of the dam happens at the water's surface elevation. The smaller the explosion distance or the more profound the water depth, the more intense the response of the CGD. Compared with the reservoir-bottom explosion, the response of the CGD is stronger when the explosion is suspended in water. Arranging a bubble curtain on the upstream surface can significantly mitigate the reservoir-bottom explosion effects on the dam, and the peak accelerations are reduced by 92.0–99.5 %. This paper can provide important references for studying the dynamic response of CGD under reservoir-bottom explosions and corresponding mitigation measures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107514"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538636","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":"Predicting shear strength of corroded RC columns: A probabilistic model with enhanced Gaussian Process Regression","authors":"Bo Yu ,&nbsp;Pengfei Zhang ,&nbsp;Bing Li","doi":"10.1016/j.istruc.2024.107551","DOIUrl":"10.1016/j.istruc.2024.107551","url":null,"abstract":"<div><div>This study proposes a new probabilistic model for predicting the shear strength of corroded reinforced concrete (RC) columns. The probabilistic model addresses limitations of traditional methods by combining mechanical understanding with enhanced Gaussian Process Regression (GPR). A novel mean function for enhanced GPR is developed first based on the shear resistance mechanism of corroded RC columns. Then the hyper-parameters of both the mean function and kernel function for the enhanced GPR are optimized using the maximum likelihood estimation method. This leads to the establishment of the probabilistic model that is based on the enhanced GPR. Finally, the accuracy and effectiveness of the enhanced GPR probabilistic model are validated by comparing it with both traditional mechanical models and machine learning models. The results indicate that the proposed probabilistic model can not only describes the probabilistic characteristics for shear strength of corroded RC columns based on probability density functions, but also provides an efficient calibration method for traditional prediction models based on confidence intervals.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107551"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538736","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":"Parallel multiple-chain DRAM probabilistic model for ultrasonic pulse velocity of concrete performance in the pipe of arch bridge","authors":"Ganzhan Ling ,&nbsp;Weiwei Xie ,&nbsp;Yu Han ,&nbsp;Ruikai Tang ,&nbsp;Jiakai Hu ,&nbsp;Ming Liang","doi":"10.1016/j.istruc.2024.107482","DOIUrl":"10.1016/j.istruc.2024.107482","url":null,"abstract":"<div><div>The existing models for predicting the compaction state of concrete inside steel tubes based on ultrasonic wave velocity have a major limitation in that they cannot comprehensively consider concrete compressive strength, instar, and various sources of uncertainties, both subjective and objective. To overcome this limitation, the study introduced a probability model for ultrasonic wave velocity in the concrete performance inside arch bridge steel tubes, based on the parallel multiple-chain Delayed Rejection Adaptive Metropolis (DRAM) algorithm. Initially, the study considers the influence of concrete compressive strength and instar, establishing a simplified deterministic model for predicting concrete compactness inside the tubes. Building on this, the study incorporates material stochastic uncertainty and cognitive uncertainty, deriving analytical expressions for a probabilistic prediction model of concrete compactness. Furthermore, using parallel processing alongside the DRAM algorithm, the study explores how the number of parallel chains and the order of acceptance probabilities influence the probabilistic model parameters. The study selected and updated the posterior distribution information of the probabilistic model parameters. Finally, the effectiveness of the model was validated using experimental data. As shown in the analysis, with better prediction accuracy and lower dispersion, the model not only selects the optimal Markov chain iteration path in a short time, but also corrects the parameters affecting the prediction accuracy of the existing model, and also provides a probabilistic method for correcting the confidence intervals of the existing model.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107482"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538634","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 and numerical investigation on vertical temperature gradient of concrete-filled steel tubular arch under sunlight","authors":"Xinkai Yan ,&nbsp;Yongjian Liu ,&nbsp;Jiang Liu ,&nbsp;Yi Lyu ,&nbsp;Xiandong Wang ,&nbsp;Jinglin Jia","doi":"10.1016/j.istruc.2024.107550","DOIUrl":"10.1016/j.istruc.2024.107550","url":null,"abstract":"<div><div>To investigate the effects of diameter and inclination on the vertical temperature gradient (VTG) of concrete-filled steel tubular (CFST) arches, this study conducted temperature field tests on three CFST segment specimens with diameters of 426 mm, 750 mm, and 1000 mm, as well as an arch specimen with inclination angles varying from 48.76° to −48.76°. 2D and 3D numerical simulation models were developed to analyze the impact of diameter, wall thickness, inclination and orientation. The results indicate that as the diameter increases, the internal temperature becomes more uniform, forming a constant temperature zone in the middle of the VTG, with linear increases in temperature differences at the top (<em>T</em>₁) and bottom (<em>T</em>₂). Beyond approximately 600 mm in diameter, the VTG stabilizes. The maximum <em>T</em>₁ of the three segment specimens were 15.37 ℃, 22.40 ℃, and 23.81 ℃, respectively. Inclination affects the solar incidence angle and intensity, causing <em>T</em>₁ to vary along the arch span, proportional to solar intensity. The maximum difference of <em>T</em>₁ in the arch specimen reached 10.87 ℃. Wall thickness showed minimal effect on the VTG. The proposed VTG pattern was applicable to arches with various orientations and can assist in evaluating thermal effects in CFST arches.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107550"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538639","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":"Research on fiber models of SRC component beam segments using the discrete element method","authors":"Qing-Yu Duan,&nbsp;Qiang Wang,&nbsp;Chun-Xiao Yang","doi":"10.1016/j.istruc.2024.107568","DOIUrl":"10.1016/j.istruc.2024.107568","url":null,"abstract":"<div><div>Accurately predicting the elasto-plastic behavior of Steel-Reinforced Concrete (SRC) components is crucial for seismic safety assessments and even collapse performance studies of buildings with such components. To enable the simulation of the entire collapse process of SRC structural buildings using the discrete element method (DEM), the steel fiber bundles have been introduced in this paper based on the segment fiber model of DEM, and the segment fiber model of SRC components (SRC-SFM) has been constructed. The internal steel and reinforcement fiber bundles have been modeled using a uniaxial steel constitutive model, while the concrete fiber bundles have been modeled using a uniaxial concrete constitutive model that takes into account the confinement effects of the steel and stirrups. The SRC-SFM has been integrated into the discrete element computational program DEM-Collapse for building structural collapse analysis, enabling it to perform mechanical performance analysis of SRC components. Through this method, the hysteretic performance of six H-shaped steel SRC test components under low-cycle repeated loading with different material parameters and axial compression ratios was simulated and analyzed to validate the reasonability of using the SRC-SFM for mechanical performance analysis of SRC components. The results show that the simulated curves from the SRC-SFM agree well with the experimental curves in terms of peak load-carrying capacity, curve shape, and stiffness degradation. The established SRC-SFM in this paper lays a solid foundation for future analysis of the entire collapse process of SRC building structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107568"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538635","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":"Tension performance of joint made in cold-formed square tube with self-tapping screw connections","authors":"Wang Yunzhe ,&nbsp;Zhou Tianhua ,&nbsp;Wang Jiqin ,&nbsp;Wang Yan ,&nbsp;Zhang Rui ,&nbsp;Li Panlong","doi":"10.1016/j.istruc.2024.107591","DOIUrl":"10.1016/j.istruc.2024.107591","url":null,"abstract":"<div><div>The tension behavior of cold-formed square tube (CFST) screw connections was investigated experimentally and numerically. Ten test specimens were fabricated from the square tubes connected by external steel plates and internal tube applying self-tapping screws such that the number of screws was varied. In addition, the mechanical properties of the single-screw connections were obtained through single shear tests. Experimental results revealed that an increase in the number of screws led to higher bearing capacity and stiffness in the specimens. Shear failure of the screws was observed as the primary failure mode. When the number of the screws was equal in both types of the specimens, those with the internal tube exhibited superior tensile behavior than the ones with external steel plates. Subsequently, finite element (FE) models of the test specimens were developed. Upon validation of the test results, an extensive parametric study was conducted to further examine the influence of the design parameters on the tensile behavior of the CFST screw connections. Variation of the arrangement of screws, wall thickness of steel plates and their strength had only a minor influence on the tension behavior, and steel strength had little influence on the tension behavior and the number, spacing, and diameter of the screws were the key parameters affecting the tension behavior of the CFST screw connections. Based on the test results and FE analyses, the existing calculation method was modified, and a formula for calculating the tensile bearing capacity of the CFST screw connections was obtained. Comparison with the results indicate that the formula was conservative and reliable for determining the tensile capacity of CFST screw connections.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107591"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538637","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":"A 2D exact model by stretching-through-the-thickness a kinematic variable for the 3D exact analysis of laminated composite structures: Theory and applications","authors":"Arno Roland Ndengna Ngatcha ,&nbsp;Joel Renaud Ngouanom Gnidakouong ,&nbsp;Lionel Merveil Anague Tabejieu ,&nbsp;Achille Germain Feumo","doi":"10.1016/j.istruc.2024.107445","DOIUrl":"10.1016/j.istruc.2024.107445","url":null,"abstract":"<div><div>The development of a rigorous exact model is of paramount importance for the enhancement of the design quality of laminated plate and shell structures for a multitude of applications. The objective of various laminated shell models developed over the past decades in the literature is to predict the three-dimensional (3D) behavior of a laminated composite shell (LCS) by the surface parameters. In this context, the original two-dimensional kinematic equations, which incorporate a variable representing stretching through the thickness, provide a novel 3D laminated constitutive equation (LCE). This novel LCE incorporates additional mechanical coupling matrices, in addition to the classical ones that are familiar to the reader. In this context, the mechanical and physical existence of the aforementioned stretching-through-the-thickness variable has been demonstrated with rigorous proof. Classical works do not present any proof of the existence of this variable. The developed LCE are combined to the Hamilton’s principle and Navier’s method to provide a new exact laminated shell model for transient analysis of composite shells. The proposed best first order exact model extends existing classical and even more recent laminated exact models developed in the literature that are based on Reissner–Mindlin theory, Kirchhoff–Love theory, high-order shear deformation theory, refined theories, Zigzag theory, Carrera’s unified formulation and many other empirical or semi-empirical theories. The best first order LCE was found to fit the experimental and theoretical outcomes documented in the literature, thereby substantiating the validity of model. The proposed exact model converges to the Classical laminated shell theory when the thickness ratio <span><math><mrow><mi>χ</mi><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>1</mn></mrow></math></span>. It is observed that the transverse and normal stress/strains are less important for thin laminated shells than for thick laminated shells. The effect of two additional mechanical couplings becomes significant when the laminated shell becomes moderately thick <span><math><mrow><mn>0</mn><mo>.</mo><mn>1</mn><mo>&lt;</mo><mi>χ</mi><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>15</mn></mrow></math></span>. When a thick shell <span><math><mrow><mn>0</mn><mo>.</mo><mn>15</mn><mo>&lt;</mo><mi>χ</mi><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>7</mn></mrow></math></span> is subjected to torsional loading, the transverse and normal strains/stresses become significant. For high order tests (<span><math><mrow><mi>N</mi><mo>=</mo><mn>2</mn><mo>,</mo><mi>N</mi><mo>=</mo><mn>3</mn></mrow></math></span>), the warping section is clearly visible.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"70 ","pages":"Article 107445"},"PeriodicalIF":3.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538638","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}