Structures最新文献

{"title":"Isolation effectiveness of lead rubber bearing on low-medium-speed maglev vehicle-bridge system under earthquake","authors":"","doi":"10.1016/j.istruc.2024.107652","DOIUrl":"10.1016/j.istruc.2024.107652","url":null,"abstract":"<div><div>The constructed maglev line generally extends for dozens of kilometers or even hundreds and thus inevitably passes across earthquake-prone regions, which exposes the viaducts to the potential risk of seismic damage. The leader rubber bearing (LRB), a commonly employed isolation support in highway and railway bridges to mitigate seismic responses, is expected to be applied into maglev line for seismic protection. However, research in this domain remains relatively scarce. This paper digs into the isolation effectiveness of LRB on low-medium-speed maglev vehicle-guideway system under earthquake. An analysis model for seismic responses of the maglev vehicle-guideway system incorporating LRB was formulated, where the maglev vehicle was simplified as a multi-rigid-body dynamic model with 50 degrees of freedom and accounted for actively-controlled electromagnetic forces. The fast nonlinear analysis technique was introduced to solve such complicated nonlinear system. Then, the seismic isolation effectiveness of LRB on the vehicle-guideway system was thoroughly investigated, and a parametric study was conducted to identify the critical factors such as pier heights and LRB dimensions that influence the isolation effectiveness. Additionally, the driving quality of vehicle moving on LRB-isolated bridge was studied to evaluate the applicability of LRB to maglev line bridge. It reveals that, the installation of LRB effectively reduces the seismic responses of bridge but enlarges the vehicle responses under earthquake. Factors including pier height, LRB initial elastic stiffness and yield force exhibit significant influence on the seismic-reduction rate for the coupling system. It is recommended that the isolation degree of LRB should not exceed 2.50 during the design of LRB-isolated bridge, thereby achieving a balance between seismic isolation effectiveness of LRBs and vehicle driving quality.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538813","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":"Failure and thermal-mechanical coupling analysis of exhaust manifold of a gasoline engine","authors":"","doi":"10.1016/j.istruc.2024.107572","DOIUrl":"10.1016/j.istruc.2024.107572","url":null,"abstract":"<div><div>Exhaust manifold is an important component of the engine system, and the failure of manifold can cause faults such as reducing power and increasing noise. This study explores the initiation and propagation characteristics of manifold failure through experimental methods such as high-temperature tensile testing, metallographic analysis, and fracture morphology of the manifold material. Finite element simulation method is adopted to investigate stress characteristics under mechanical and thermal-mechanical coupling loads. The maximum thermal-mechanical coupling stress of the exhaust manifold reaches 150 MPa, and it located coincides with the failure point. The high stress distribution of thermal-mechanical coupling is consistent with the failure experimental study results. The combination of simulation and experiment identified the causes of manifold failure and provided measures to improve the thermal fatigue resistance of the manifold.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538892","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 study on seismic performance of bridge pier with new HRB650E high-strength steel bar","authors":"","doi":"10.1016/j.istruc.2024.107650","DOIUrl":"10.1016/j.istruc.2024.107650","url":null,"abstract":"<div><div>To facilitate the application of high-strength steel in reinforced concrete bridge structures, this study explores the seismic performance of full-scale HRB650E high-strength reinforced concrete bridge piers. Initially, monotonic tensile tests were conducted on HRB400 and HRB650E steel rebars with the same slenderness ratio to analyze the differences in their mechanical properties. Subsequently, quasi-static cyclic tests were carried out on four square full-scale RC bridge piers to examine the influence of new high-strength rebars, stirrup ratios, and axial load ratios on the seismic performance. Based on the experimental results, a hysteresis model suitable for HRB650E reinforced concrete columns was developed. The findings indicate that the HRB650E steel bar exhibited lower uniform elongation and fracture elongation compared to HRB400 steel bar. The displacement at which HRB650E piers reached crack damage was 36 % higher than that of HRB400 piers, and they also showed lower residual displacements at all load levels. The maximum lateral load capacity and the ductility coefficient of HRB650E piers increased significantly compared to HRB400 piers. While the initial secant stiffness of both types was comparable, HRB650E piers exhibited a slower rate of stiffness degradation, resulting in higher secant stiffness at the ultimate state. They also demonstrated 35 % higher cumulative energy dissipation at the ultimate state. When the stirrup ratio of HRB650E piers was increased from 1.1 % to 1.7 %, there was a slight reduction in residual displacement, a small increase of the yield strength, and a minor improvement in the maximum lateral load capacity. Furthermore, a higher stirrup ratio was observed to improve energy dissipation levels at all loading stages. Increasing the axial load ratio of HRB650E piers from 0.1 to 0.2 allowed the piers to withstand greater deformations at the same repairable ultimate state, with significant increases in yield strength, maximum lateral load capacity, initial secant stiffness, and secant stiffness at the ultimate state, but a small increase in the cumulative energy dissipation. The hysteresis model for HRB650E RC columns, based on experimental data, exhibited good computational accuracy.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538811","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 shear-force-based Bridge Weigh-in Motion approach for simple supported structures","authors":"","doi":"10.1016/j.istruc.2024.107607","DOIUrl":"10.1016/j.istruc.2024.107607","url":null,"abstract":"<div><div>This paper introduces a shear-force-based Bridge Weigh-In-Motion (B-WIM) approach for simply supported structures. Instead of using rosette sensors for shear strain calculation, this method derives shear data from strain measurements taken with strain gauges positioned at the middle of the cross-section, inclined at 45°, near the support. A significant practical advantage of this sensor setup over the rosette configuration is that it requires only one strain gauge per girder to capture the necessary field data. The theoretical basis of this sensor arrangement and its integration into the B-WIM method are thoroughly explained. To evaluate the effectiveness of the proposed approach, its performance is compared to an equivalent bending B-WIM approach using numerical data. Then, in order to assess the proposed approach in practice, a Brazilian simply supported prestressed concrete bridge was instrumented to gather both bending data, based on axial strain in the middle of the span, and shear data near the supports. The results showed that the utilization of the shear based approach provided a substantial reduction in the mean absolute error in axle weight estimation, along with a decrease in the error standard deviation, both in numerical and in real-world B-WIM data. These findings demonstrate the efficacy of the proposed shear based B-WIM approach in improving axle weight estimation for road bridges, while also maintaining accurate predictions for gross vehicle weight. Furthermore, this study is the first in the literature to demonstrate the advantages of using shear data over bending data for B-WIM applications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538816","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":"Modeling of floating roof tanks under seismic excitation, accounting for the influence of sealing system and the roof pounding","authors":"","doi":"10.1016/j.istruc.2024.107590","DOIUrl":"10.1016/j.istruc.2024.107590","url":null,"abstract":"<div><div>This paper presents a complete finite element (FE) model of an atmospheric tanks with floating roof and sealing system to analyze its seismic behavior under earthquake excitation, while also exploring simplified modeling approaches for faster assessments. The modeling of atmospheric tanks with floating roofs subjected to earthquakes, focusing on the presence of the mechanical spring seal system and roof-wall pounding, is described. A complete finite element model including the tank, fluid, roof, sealing system, and pounding has been developed using the Arbitrary Lagrangian–Eulerian (ALE) approach in Abaqus. Seismic analyses were performed with different earthquakes. Simplified models were also explored by decoupling the vertical and horizontal roof motion components. Vertical motion was analyzed with a literature model and horizontal motion with a single-degree-of-freedom vibro-impacting system with rigid impact. The results demonstrate the effectiveness of the complete FE model in simulating seismic behavior of floating roof tank with sealing system and the use of simplified models for faster, more accurate analyses.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538850","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":"Study on the optimal thickness ratio of steel-aramid composite structure against local explosion","authors":"","doi":"10.1016/j.istruc.2024.107657","DOIUrl":"10.1016/j.istruc.2024.107657","url":null,"abstract":"<div><div>Previous studies of the steel-aramid anti-explosion structure have not dealt with the optimal thickness ratio of the steel and the aramid layers. In this paper, the damage mechanism of aramid-steel composite (ASCTs) target plate with single layer and multiple structural configurations under local explosion load is studied by experimental and numerical simulation methods. The influence of different thickness combinations on the anti-explosion performance of aramid composite structure was compared, and the thickness combination mode with the best cost performance was analyzed. The optimal structure anti-explosion design scheme was obtained by using the optimization method. The optimal thickness ratio has been analyzed, and the optimal anti-explosion structure design has been given. Experimental results show that at the same proportional blast distance (200 g TNT), the Q235 steel-aramid laminate target suffered no structural failure and its centre deflection was 10 % less than single-layer steel (S-1). The same thickness steel sheet (S-2) without the aramid laminate failed to perform as expected. The numerical simulation results show that at a proportional blast distance of 0.16 m/kg^1/3, the best blast protection thickness ratio of the Q235 steel-aramid protective structure is 2.6:9.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538852","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":"Auxetic structures with viscoelastic behavior: A review of mechanisms, simulation, and future perspectives","authors":"","doi":"10.1016/j.istruc.2024.107610","DOIUrl":"10.1016/j.istruc.2024.107610","url":null,"abstract":"<div><div>The combination of an auxetic structure featuring a negative Poisson’s ratio (NPR) and viscoelastic materials with superior damping behavior and energy absorption introduces a collaborative strategy that utilizes the distinct properties inherent in each category. This provides numerous advantages across various applications, enabling viscoelastic auxetic materials (VAMs) not only to resist deformation but also to dynamically adjust to changing conditions. In these regard, numerous investigations into constitutive models for VAMs have been conducted, exploring a range of structural architectures, materials simulations, experimental methodologies, static and dynamic performance, and practical applications. To clarify the unique potentials of VAMs in various fields, this review presents a summary of structural configurations and classification of materials, considering exceptional mechanical properties of the auxetic structure coupled with viscoelastic behavior. The objective of this study is to provide a comprehensive overview of numerical analysis and fabrication techniques, while also addressing the challenges associated with the implementation of viscoelastic-based auxetic structures and elucidating their capabilities.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538817","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":"Study on the mechanical properties of hybrid bonding shear connections with shear studs and epoxy mortar layer","authors":"","doi":"10.1016/j.istruc.2024.107642","DOIUrl":"10.1016/j.istruc.2024.107642","url":null,"abstract":"<div><div>This paper designed a new type of hybrid bonding (HB) shear connections consisting of both epoxy mortar layer and shear studs, to avoid the shortcomings such as stress concentrations and welding defects accompanied with the use of the traditional stud connectors in composite structures. In order to study the mechanical behavior of the hybrid connections in a systematic fashion, this work carried out several experimental tests, including measurement under static loads and push-out tests on specimens with epoxy-mortar shear connections and hybrid connections containing single stud and group studs, respectively. During those experiments, several parameters that affected the mechanical behavior of the connectors were investigated, such as the failure mode, interfacial slip, as well as the load-displacement relation and bonding capacity, etc. It was demonstrated that the shear capacity of the specimens with hybrid shear connection was generally higher than that with pure shear studs. What’s more, it was found that the failure/debonding could appear at interfaces between adhesive layer and steel girders/concrete structures. The aforementioned experiments illustrated that the epoxy mortar layers possessed excellent shear capacity and effectively avoided the stress concentrations by the shear studs. Regarding the post-debonding process, hybrid connections exhibited similar mechanical behavior as the shear studs within the epoxy mortar layer. In general, it is concluded that the proposed hybrid connection is superior and is recommended for the shear connection of composite structures relative to the traditional stud connectors.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538819","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":"Machine learning (ML) algorithms for seismic vulnerability assessment of school buildings in high-intensity seismic zones","authors":"","doi":"10.1016/j.istruc.2024.107639","DOIUrl":"10.1016/j.istruc.2024.107639","url":null,"abstract":"<div><div>Ensuring seismic resilience of school buildings is crucial for safeguarding their occupants during earthquakes. This paper focuses on assessing the seismic vulnerability of school buildings constructed in the Kashmir region of Pakistan after the 2005 earthquake, which claimed the lives of 19,000 school-going children. It explores the feasibility of utilizing machine learning (ML) algorithms for enhanced rapid screening of schools to establish fragility information. The study is based on data collected in the Kashmir region and focuses on assessing representative reinforced concrete (RC) and unreinforced masonry (URM) school buildings. To determine structural fragility curves, Incremental Dynamic Analyses (IDA) are performed, simulating fifteen historical earthquakes. Four different ML models are investigated to predict fragility curves, including Random Forest (RF), Artificial Neural Networks (ANNs), Extreme Gradient Boosting (XGBoost), and Extremely Randomized Tree Regressor (ERTR). The performance of the algorithms is compared using performance metrics such as precision, accuracy, and f1 score. The study identified XGBoost and RF as the highest performing algorithms, achieving highly satisfactory accuracy with the correlation coefficients of 0.91 and 0.81 for RC schools, and 0.88 and 0.83 for URM schools during testing phases. Alternatively, ERTR’s performance could not justify its use for structural seismic vulnerability assessments. This highlights the significant potential of using ML algorithms for automated seismic vulnerability evaluation of buildings, greatly reducing the overall computational burden while maintaining high accuracy and reliability.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538946","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":"Consistent Exponential Control algorithm for building structures","authors":"","doi":"10.1016/j.istruc.2024.107528","DOIUrl":"10.1016/j.istruc.2024.107528","url":null,"abstract":"<div><div>This paper introduces a novel controller termed Consistent Exponential Control, which combines the desired control force and voltage generation strategy necessary for activating MR dampers individually in a base-isolated reference building. By establishing an inverse model of a specific MR damper based on the modified Kwok model, an appropriate control voltage is generated for each damper, considering potential rotational effects of the structure induced by external excitations. The output voltage is a continuous parameter that ranges from zero to one. All procedures are validated using a framework provided by the American Control Association for base-isolated benchmark problems. Hence, this study represents a comprehensive endeavor that includes device identification, model development, inverse modeling, and the final control algorithm. The numerical results of the simulations demonstrate the outstanding effectiveness of the proposed exponential control algorithm.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538948","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}