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Finite Element Modelling of Steel Beams with Web Openings

engineering（科研） 2014年第13期6卷 886-913页

作者： Flavio Rodrigues Pedro C. G. da S. Vellasco Luciano R. O. de Lima Sebastiã o A. L. de Andrade PGECIV—Post Graduate Program in Civil Engineering UERJ—State University of Rio de Janeiro Rio de Janeiro Brazil Structural Engineering Department UERJ—State University of Rio de Janeiro Rio de Janeiro Brazil

Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath steel beams leading to uneconomic floor heights. The most adopted solution for this issue is the use of steel beam web openings to provide the required space for services. These openings could lead to a significant decrease of the beam load carrying capacity depending on the adopted openings shape, size and location. These aspects motivated the present study based on FE simulations calibrated against numerical and test results. The results accuracy enabled a comprehensive parametric analysis of beams with web openings to be made focused on the profile size, web opening location, among others. The study also investigated the efficiency of longitudinal stiffeners welded at the opening region and benefits of using an adequate edge concordance radius in beams with rectangular and square openings. The obtained results showed the need of using welded longitudinal stiffeners in order to increase the beams ultimate load carrying capacity. This adoption can double or even triple the ultimate load of beams with rectangular and square opening heights equal to 0.75 H, respectively.

关键词： Non-Linear Analysis Steel Structures Web Openings Steel Design and Behavior Finite Element Method

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Design and Construction of Smart Cities 1

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丛书名： Sustainable civil Infrastructures

1000年

作者： Ibrahim El Dimeery Moustafa Baraka Mona B. Anwar Mahmoud El Khafif Nagy Hanna Syed M. Ahmed Amin Akhnoukh Amr T. Abdel Hamid

ISBN: (数字)9783030642174

ISBN: (纸本)9783030642167

This book focuses on how to maintain environmental sustainability as one of its main principles, and it addresses how smart cities serve to diminish wastes and maintain natural resources by having clean green energy that is operated by new smart technology designs. Living in a smart city is not something of the future anymore, it is here, and it is being implemented all over the world. A smart city uses different types of electronic Internet of things (IoT) sensors to collect data and then use these data to manage assets and resources efficiently. The smart city concept integrates information and communication technology (ICT), and various physical devices connected to the IoT network to optimize the efficiency of city operations and services and achieve sustainable solutions to allow us to grow with proper management of our resources.;Smart sustainable structures and infrastructures face the need of urban areas due to the growth of populations while in the same timesave our environment. To achieve this, we need to revisit the conventional methods in design and construction and the conventional materials which are used now to optimize the design and provide smart solutions. In the past few years, the consumption of resources has been massive, and the waste produced from that consumption has been inconceivable. This is causing environmental degradation, which produces many environmental challenges, such as global climate change, excessive fossil fuel dependency and the growing demand for energy.;As well as, discussing the challenges facing the civil engineering design and construction of smart cities components and presenting concepts and insight from experts and researchers from different civil engineering disciplines., this book explains how to construct buildings and special structures and how to manage and monitor energy.

关键词： Earth Sciences, general Geotechnical engineering & Applied Earth Sciences

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A feasibility study of recycling of construction and demolition waste for structural purposes

Journal of Solid Waste Technology and Management

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Journal of Solid Waste Technology and Management 2013年第3期39卷 204-213页

作者： Mariano, Leila Seleme Da Costa, Marienne Do Rocio De Mello Maron Braga, Maria Cristina Borba Brasilian Air Force Integrated Air Traffic and Control Center - CINDACTA II Brazil Parana Federal University Department of Civil Engineering Civil Engineering Post-Graduate Program Brazil Parana Federal University Department of Hydraulics and Sanitation Water Resources and Environmental Engineering Post-Graduate Program Brazil Universidade Federal do Paraná Setor de Tecnologia Centro Politécnico - Jardim das Américas CxP 19011 81531-980 Curitiba - Paraná Brazil

The environmental problems related to construction and demolition waste involve their final dis-posal and the use of raw materials. The main goal of this research was to manage on site con-struction and demolition waste and generate concrete for structural purposes by processing concrete and mortar wastes. A Construction and Demolition Waste Management Plan (CDWMP) was developed for this study and applied by means of the implementation of recy-cling procedures. This plan included quantifying wastes and analyzing their generation. The concrete and mortar wastes were separated for recycling to produce concrete in which these wastes, respectively, replaced fractions of coarse aggregate (crushed stone) and fine aggre-gate (sand). Tests were carried out to characterize the resulting concrete and the aggregates used. The strength of the concrete generated varied from 6 MPa to 21.4 MPa, for the same mixture. It was observed that structural concretes can be produced using recycled aggregates, however this cost is higher compared to that of concrete produced with conventional aggre-gates. It was also concluded that despite the cost of concrete production, there were environmental and economic advantages to performing and applying the CDWMP to this specific con-struction site. Copyright © 2013 Widener University.

关键词： Recycling

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Assessing the performance of eggshell ash as a sustainable bitumen modifier

Transportation Engineering

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Transportation engineering 2023年 13卷

作者： Syammaun, Tamalkhani Husaini Abdullah Isya, Muhammad Rachman, Firmansyah Doctoral Program School of Engineering Post Graduate Program Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Muhammadiyah Aceh Banda Aceh23123 Indonesia Department of Mechanical Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia

The disposal of eggshells in landfills presents an ongoing global environmental issue that demands immediate attention. However, a promising solution lies in utilizing eggshells as modifiers in bitumen binders, offering a sustainable approach to alleviating this burden. This study focuses on crushing eggshells to produce eggshell ash, which is then explored as a potential modifier in bitumen binders. The objective is to evaluate the properties of modified bitumen binders incorporating eggshell waste sourced from the food industry and examine their application in bitumen engineering. The optimal weight percentage of eggshell ash in the bitumen is determined, considering four levels (5, 7, 10 and 12%) and two heating temperatures (100 and 200 °C). Several tests are conducted to comprehensively evaluate the eggshell ash, including SEM-EDS and FTIR analyses, providing valuable technical insights into its properties. Additionally, DSR measurements are employed to analyze the characteristics of the bitumen incorporating eggshell ash. The primary oxide group present in the eggshell ash is CaCO3. Notably, higher concentrations of eggshell ash enhance the resistance of bitumen binders to high temperatures, as indicated by the penetration index results. Furthermore, DSR testing reveals that adding eggshell ash increases the rigidity of the bitumen binders, resulting in improved resistance to deformation. © 2023 The Author(s)

关键词： Binders

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Assessment of Stainless Steel Tubular T-joints Under Chord Sidewall Failure Mode by a Semi-analytical Formulation

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ce/papers 2022年第4期5卷 574-583页

作者： Nogueira, Mateus M. de Lima, Luciano R. O. da S. Vellasco, Pedro C. G. Young, Ben PGECIV - Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong

There are numerous benefits of tubular profiles that make them increasingly used in civil engineering. At the same time, stainless steel is a material with excellent properties and high corrosion resistance. However, stainless steel's high initial material cost has limited its use primarily to specialist and prestige applications, which makes it necessary to develop more accurate design rules for this material. When tubular profiles are used, it is necessary to assess the joint strengths, considering that they can fail by different mechanisms. The present work aims to develop a semi-analytical formulation to predict stainless steel tubular T-joint resistances. Joints with the brace-to-chord width ratio equal to 1 were considered in this study;therefore, the failure occurs in the chord sidewall. To assess the sidewall instability critical load, the exact stress fields were determined using Mathieu's theory, and then the Ritz energy method was applied. Considering that the joints are made of stainless steel, the next step is to transform the load found from linear to the non-linear regime. For that, a new formulation based on Ramberg-Osgood equations was developed. Finally, the results obtained from the proposed method were compared with the experimental results obtained by Feng and Young (2008) and the results from the main current standards and literature. It was observed that the proposed method presented satisfactory results, while the predictions from design codes were, in general, very conservative. © 2022 Ernst & Sohn GmbH.

关键词： Failure (mechanical)

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Numerical assessment of stainless steel tubular T-joints subjected to brace and chord axial forces

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ce/papers 2021年第2-4期4卷 2495-2503页

The utilisation of tubular sections in steel structures has increased significantly worldwide. The use of stainless steel provides several benefits for structures, including high corrosion resistance, durability, fire resistance and ease of maintenance. A significant issue in the design of tubular structures is the joints failure since they are highly susceptible to local failures that influence their actual overall behavior. The design rules of welded carbon steel tubular joints are available, such as Eurocode 3, part 1-8, NBR 16239, ISO 14346 and CIDECT guides. When stainless steel tubular joints are considered, the AS/NZS 4673 Australian/New Zealand Standard is the only available specification that can be used. An experimental and numerical analysis of these tubular joints are recommended since they enable a more accurate evaluation of their structural performance. Concerning these aspects, this work aims to investigate stainless steel tubular T-joints fabricated by SHS and RHS cold-formed profiles that focused on the effect of chord pre-loading. For this purpose, a numerical study based on finite element analysis was performed. The finite element model was developed and calibrated against experiments. The results were subsequently compared with the aforementioned design predictions. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Finite element method

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Influence of recycled aggregate on the rheological behavior of cement mortar

Influence of recycled aggregate on the rheological behavior ...

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14th International Conference on Non-Conventional Materials and Technologies for Sustainable engineering, NOCMAT 2013

作者： Lima, Paulo Roberto Lopes Filho, Romildo Dias Toledo Da Fonseca Martins Gomes, Otávio 1Post-graduate Program of Civil and Environmental Engineering Department of Technology State University of Feira de Santana Av. Transnordestina S/N-Novo Horizonte Feira de Santana Bahia 44036-900 Brazil Civil Engineering Program/COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil Centre for Mineral Technology-CETEM Av. Pedro Calmon 900 21941-908 Rio de Janeiro Brazil University of Liege GeMMe Georesources and Geoimaging Sart Tilman B52 4000 Liege Belgium

ISBN: (纸本)9783037859810

In this work it was studied the influence of recycled fine aggregate obtained from construction and demolition waste (CDW) on the rheological properties of Portland cement mortars. The CDW was initially separate in their main constituents (mortar, ceramic and concrete debris) at the laboratory and then grinded separately to the sand size in order to generate more homogeneous fine aggregates. The characterization of the natural and recycled sands was carried out through physical tests, X-ray diffraction, scanning electron microscopy (SEM), and image analysis (shape and texture description parameters). A conventional mortar and three mortars containing recycled sands were produced with a sand/cement ratio of 4 and consistency index of 255±5 mm. The consistency was kept constant by ranging the water-cement ratio from 0.58 to 1.14. The rheological study was performed using a rotating viscometer to obtain torque-rotation ratio and to calculate the yield stress and plastic viscosity. The results indicate that the presence of recycled aggregate causes a lowering of both yield stress and plastic viscosity with respect to the mortar containing natural aggregate. © (2014) Trans Tech Publications, Switzerland.

关键词： Mortar

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An Investigation of Hydro-morphology Contributory Factors in Flooding and Sedimentation Problems on the Krueng Buloh River, Indonesia

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Open civil engineering Journal 2023年 17卷

作者： Listia, Vina Munirwansyah, Munirwansyah Azmeri, Azmeri Yulianur, Alfiansyah Doctoral Program School of Engineering Post Graduate Program Universitas Syiah Kuala Banda Aceh Darussalam 23111 Indonesia Department of Civil Engineering Faculty of Engineering Universitas Syiah Kuala Banda Aceh Darussalam 23111 Indonesia

Introduction: Process-based river hydrology and morphological analyses are infrequent, especially in developing countries. Climate change and the expected occurrence of major floods and erosion that could threaten the safety of nearby and downstream settlements, especially in areas that are very sensitive and affected by global warming, have made this kind of investigation necessary. Methods: The watershed of the River Krueng Buloh is prone to severe flooding, which has many social and economic effects on the villages nearby, such as the loss of crops and the destruction of buildings. However, the hydro-morphology and fluctuation of this river have not yet been studied. This research aims to determine which factors influence the stability of a river channel in the downstream region of the Krueng Buloh watershed following flooding or erosion. Results: To achieve this objective, field, and satellite-based observations of the hydro-morphology of a Krueng Buloh watershed have been performed. The investigation reveals that floods and sediment accumulation in the floodplain were triggered by excessive rainfall, the meandering of the river, and the riverbank soil type. Conclusion: The conclusions and methods given can be used to evaluate flooding and sedimentation in rivers for future operations to protect and preserve rivers. © 2023 Listia et al.

关键词： Erosion Flood Hydrology Morphology River Sedimentation Watershed

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Evaluation of the Performance of Different Damage Indicators in Railway Bridges

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Procedia engineering 2015年 114卷 746-753页

作者： Vinicius Alves Andreia Meixedo Diogo Ribeiro Rui Calçada Alexandre Cury Post-Graduate Program in Civil Engineering Federal University of Ouro Preto Ouro Preto Brazil Faculty of Engineering University of Porto Porto Portugal School of Engineering Polytechnic of Porto Porto Portugal Departament of Applied and Computational Mechanics Federal University of Juiz de Fora Juiz de Fora Brazil

This article describes a damage identification methodology based on a genetic algorithm and its application to the numerical model of a railway bridge. The identification method is based on an iterative process that in each iteration compares the values of the bridge's dynamic response for a test damage scenario with the response values for a reference damage scenario. The introduction of damage to the test numerical model is based on the modification of a preselected numerical parameter values. The genetic algorithm allows the identification of damage by minimizing the residue of an objective function constructed from the responses of the test and reference model, and based on the so-called damage indicators. In this study are defined and tested damage indicators based on modal parameters (frequencies and vibration modes) in parameters built from the modal parameters (modal curvatures and flexibility curvatures), and in dynamic responses under action of impulsive loads from frequency response functions (FRFs). The proposed methodology for identifying damage was tested based on a two-dimensional numerical finite element model of a railway bridge including the railway track. The results allowed evaluating the efficiency and reliability of the methodology and of the damage indicators which, in most situations, showed potential in the detection, location and quantification of the severity of the damage.

关键词： Damage identification iterative method genetic algorithm damage indicators railway bridges.

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Study of Machine Learning Techniques for Damage Identification in a Beam 10th

Study of Machine Learning Techniques for Damage Identifica...

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10th International Conference on Wave Mechanics and Vibrations, WMVC 2022

作者： da Silva Coelho, Jefferson de Sousa, Amanda Aryda Silva Rodrigues Machado, Marcela Rodrigues Dutkiewicz, Maciej Department of Mechanical Engineering University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília Brazil Post-Graduate Program - Integrity of Engineering Materials University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília70910-900 Brazil Faculty of Civil Environmental Engineering and Architecture University of Science and Technology Bydgoszcz85-796 Poland

ISBN: (纸本)9783031157578

Damage is defined as any change to the material, geometry or boundary condition that can modify the structure’s properties or response. In the past, damage identification was performed through periodical inspection, non-destructive testing/non-destructive evaluation, or visual observation. Structural health monitoring (SHM) has emerged to transition from offline damage identification to near real-time and online damage assessment. Hence, SHM is a damage detection strategy to monitor a structure for a period using a series of continuous measurement devices, which then collect the system’s characteristics and subsequently perform statistical analysis to assess the current circumstances and health of the structure. One of the first steps for the study of SHM is damage detection followed by monitoring. Machine Learning (ML) techniques can be used to develop viable algorithms to make potential predictions. ML algorithms are therefore providing the tools needed to enhance the capabilities of SHM systems and provide intelligent solutions to past challenges. Preliminary studies have reviewed that the extension of ML into SHM has dramatically increased the system’s capabilities, providing innovative solutions to different research challenges. This work conducts a study of the use of ML to identify damage in a beam and discuss the challenge of usage, performance and implementation of each technique. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Decision trees

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