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Proceedings of the 15th International Symposium on Tubular Structures, ISTS 2015

作者： Amparo, L.R. Sarmanho, A.M. De Araújo, A. Requena, J. Post-Graduate Program in Civil Engineering Federal University of Ouro Preto Ouro PretoMG Brazil V&M do Brasil S. A Belo HorizonteMG Brazil State University of Campinas CampinasSP Brazil

ISBN: (纸本)9781138028371

Steel circular hollowsections (CHS) have good resistance under tension, compression and torsion loads, considered isolated or combined. Recent researches have been carried out to evaluate the behavior and resistance of these structures. A current use of steel hollow sections is roof trusses, a kind of structure that demands standard procedures and fast assemblage. This work presents an experimental study of a new type of connection called sleeve, developed to attend the assembly process. The connection consists of two tubes internally connected through a third tube with a smaller diameter with passing bolts arranged in line and cross. This connection makes easier the structure assemblage and is aesthetically advantageous if compared to usual flanged connection used in hollow sections. An experimental program of the sleeve connection with bolts in line (along the tube) and crossed at 90◦ was developed. In this work were tested 3 prototypes with staggered bolts to complement previous research and 12 prototypes with crossed bolts. The parameters considered in investigation were tube diameter and thickness and number of bolts. Experimental results lead to identification of failure mode and the resistance of sleeve connection. The analysis of theoretical and experimental data revealed that the dominant failure mode was bending in the bolts, and indicated a reduction in connection resistance that needs to be quantified. For the prototypes with staggered bolts, the analysis also let the development of an expression for the determination of flexural failure in the bolts. The results have demonstrated the viability of this new type of connection, but indicated that all possible failure modes need to be carefully checked. © 2015 Taylor & Francis Group, London.

关键词： Failure modes

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Experimental Assessment of Stainless and Carbon Steel Double-Skin Tubular Stub Columns Filled with Recycled Aggregate Concrete

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ce/papers 2021年第2-4期4卷 764-771页

作者： Castanheira, Deborah S. de Lima, Luciano R. O. Vellasco, Pedro C. G. da S. Cashell, Katherine A. Gardner, Leroy PGECIV - Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Department of Civil and Environmental Engineering Imperial College London London United Kingdom Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Department of Civil and Environmental Engineering Brunel University London United Kingdom

This paper presents an experimental study into the behaviour of concrete filled double skin tubular (CFDST) stub columns. A total of eight axial compression tests were carried out, half of which were filled with conventional concrete and the remainder had recycled aggregate concrete. The columns were circular in cross-section and comprised an austenitic stainless steel outer tube and a carbon steel inner tube, of varying dimensions. Accordingly, hollow ratios of 0.67 and 0.55 were considered. The recycled coarse aggregate was made by crushing test specimens from a previous research project. A replacement ratio of 50% was adopted in these tests. Both the natural coarse aggregates and the recycled aggregates had a maximum diameter of 9.5 mm. During the tests, similar structural behaviour and failure modes were observed between the columns with conventional and recycled aggregate concrete, and the faiure modes were identical. The experimental results are compared with available design procedures and it is ultimately shown that using recycled aggregate concrete rather than regular concrete in CFDST stub columns does not have a significant effect on the performance. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Compression testing

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Human Comfort Evaluation of a Steel-Concrete Composite Building Subjected to Aerobics

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Journal of civil engineering and Architecture 2016年第11期10卷 1259-1269页

作者： Jose Guilherme S. da Silva Ana Cristina C. F. Sieira Fernanda F. Campista Caissio M. R. Gaspar Structural Engineering Department (ESTR) State University of Rio de Janeiro (UERJ) Rio de Janeiro 20550-900 Brazil Civil Engineering Post-graduate Programme (PGECIV) State University of Rio de Janeiro (UEILI) Rio de Janeiro 20550-900 Brazil

The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.

关键词： Steel-concrete composite floors structural dynamics vibration analysis human comfort computational modelling.

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Dynamic Analysis of Steel Platforms When Subjected to Mechanical Equipment-Induced Vibrations

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Journal of civil engineering and Architecture 2016年第10期10卷 1103-1113页

作者： Jose Guilherme S. da Silva Ana Cristina C. F. Sieir~ Luis A. P. Simoes da Silva Bruno D. Rimola Structural Engineering Department (ESTR) State University of Rio de Janeiro (UERJ) Rio de Janeiro 20550-900 Brazil Civil Engineering Post-graduate Programme (PGECIV) State University of Rio de Janeiro (UERJ) Rio de Janeiro 20550-900Brazil Civil Engineering Department University of Coimbra Coimbra 3030-788 Portugal

The competitive trends of the world market have long been forcing structural engineers to develop minimum weight and labour cost solutions. A direct consequence of this new design trend has been a considerable increase in problems related to undesired floor vibrations. For this reason, structural floor systems can become vulnerable to excessive vibrations that are produced by, for example, impacts due to mechanical equipment （e.g., rotating machinery）. This study investigates the dynamic behaviour of a production platform constructed of steel and located in the Santos Basin （Merluza field）, Sao Paulo/SP, Brazil, when subjected to impacts produced by mechanical equipment （rotating machinery）. The structural model consists of two steel decks with a total area of 1,915 m^2 （upper deck： 445 m^2, lower deck： 1,470 m^2） and supported by piles. A numerical analysis is performed to assess the dynamic impacts on the deck structure originating from the electrical generators and compressors. Based on the peak acceleration values obtained for the structure steady-state response, it is possible to evaluate the structural model performance in terms of human comfort, the maximum tolerances of the mechanical equipment and the vibration serviceability limit states of the structure.

关键词： Dynamic analysis steel structures production platforms human comfort structural behaviour computational modelling

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Dynamic analysis of steel-concrete composite tubular footbridges submitted to human walking

Dynamic analysis of steel-concrete composite tubular footbri...

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4th International Conference on Computational Methods in Structural Dynamics and Earthquake engineering, COMPDYN 2013

作者： Debona, Gilvan L. Da Silva, José G. S. Sieira, Ana C. C. F. Civil Engineering Post-graduate Programme PGECIV State University of Rio de Janeiro UERJ São Francisco Xavier St. 524 Maracanã 20550-900 Rio de Janeiro RJ Brazil Structural Engineering Department ESTR State University of Rio de Janeiro UERJ São Francisco Xavier St. 524 Maracanã 20550-900 Rio de Janeiro RJ Brazil

ISBN: (纸本)9789609999427

The increasing incidence of footbridges excessive vibration problems due to human walking induced loads led to an increase in the number of complaints arising from annoying human-induced vibrations in new footbridge structures. Based on the improvements in design methods, structural engineers seem to continuously move the safety border to increase slenderness and lightness of their footbridges using more slender structural designs. Considering all aspects mentioned before, this was the main motivation for the development of a finite element modelling of the dynamic behaviour of steel-concrete composite tubular footbridges, when subjected to human walking vibrations. The investigated structural system was based on a steel-concrete composite tubular footbridge spanning 82.5 m. The structural model consists of tubular steel sections and a concrete slab. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element modelling. The finite element model enabled a complete dynamic evaluation of the composite tubular footbridge in terms of human comfort and its associated vibration serviceability limit states. The peak accelerations found in the present analysis indicated that the investigated footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge user's comfort.

关键词： Structural dynamics

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Study of damage distribution and intensity in regions of the facade

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Journal of Building Pathology and Rehabilitation 2016年第1期1卷 1-9页

作者： de Souza, Jessica S. Bauer, Elton Nascimento, Matheus L. M. Capuzzo, Valdirene M. S. Zanoni, Vanda A. G. Post-Graduate Program in Structures and Civil Construction Civil and Environmental Engineering Department University of Brasília Campus Universitário Darcy Ribeiro Asa Norte Brasília 70910-900 DF Brazil Faculty of Architecture and Urbanism University of Brasília Campus Universitário Darcy Ribeiro Asa Norte Brasília 70910-900 DF Brazil

The ceramic coating systems applied to building facades have relevant aesthetic value and protection functions. The architectural and environmental conditions can greatly influence the degradation process of the facades, which may pose risks and compromise the durability and service life of the building and its components. The degradation process of facades changes according to the region where it takes place. To this end, the present study aims to determine damage intensity and distribution in the different regions of the facade. This study investigated the facades of three buildings that are part of the Materials Testing Laboratory (LEM) database of the Universidade de Brasilia. The degradation was quantified using a methodology proposed by Silva (2014) to generate a degradation index expressed in m². After the quantification of damages, few indexes associated with the percentage of degraded area, applied to the facade regions, are presented. These weighted indexes allowed to standardize the values observed in each region. Obtaining these indices is fundamental to the study of degradation. The results show that for a comparative analysis between the regions, the observed values should be corrected for the proportionality of the area of each region in relation to the total area of the facade. It was also noted that the continuous walls are the most affected regions, but they do not always present the highest damage intensity. © 2016, Springer International Publishing Switzerland.

关键词： Damage distribution Degradation Degradation index Facades Pathology

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Wind-driven rain incidence parameters obtained by hygrothermal simulation

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Journal of Building Pathology and Rehabilitation 2016年第1期1卷 1-7页

作者： Nascimento, M.L.M. Bauer, E. de Souza, J.S. Zanoni, V.A.G. Post-Graduate Program in Structures and Civil Construction Civil and Environmental Engineering Department University of Brasília Campus Universitário Darcy Ribeiro Asa Norte Brasília 70910-900 DF Brazil Faculty of Architecture and Urbanism University of Brasília Campus Universitário Darcy Ribeiro Asa Norte Brasília 70910-900 DF Brazil

The association of rain and wind composes wind-driven rain (WDR), and its incidence may be crucial to the emergence of anomalies on the facades of buildings. Moisture from the WDR can influence the humidification and drying process, therefore the durability and hygrothermal performance are conditioned by the amount of incident water. The quantification of WDR can be an indispensable tool for understanding its related phenomena and the service life of buildings. The most widely used methods of quantification are the semi-empirical, with theoretical basis, but coefficients partially determined from measurements. These methods may take into account the building exposure conditions related to the envelope, solar orientation, height of the building, and other parameters. In this context, in order to contribute to the studies on quantification of WDR, the purpose of this paper is to apply hygrothermal simulation software WUFI^® on quantification of WDR focusing on buildings degradation of Brasília-Brazil. For the simulation it was used a Typical Meteorological Year file with the wind and precipitation measurement data indispensable for simulation. The quantification of incidence of WDR considered the orientations North, Northeast, East, Southeast, South, Southwest, West, and Northwest. The use of semi-empirical WUFI^® quantification method allowed finding the highest values and consequently critical orientations North, Northwest, and Northeast, moreover, this results showed the relation with the degradation of facades in these orientations. WUFI proved to be an easy, fast and efficient method of WDR quantification, without hiding seasonal weather effects. © 2016, Springer International Publishing Switzerland.

关键词： Degradation Facade Hygrothermal simulation Wind-driven rain

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Study of soil structure interaction on basement wall with variants in distance and depth of the basement on soil class SE 2

Study of soil structure interaction on basement wall with va...

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2nd Joint International Conference on Emerging Computing Technology and Sports, JICETS 2019

作者： Saragi, Yetty Irsyam, Masyhur Roesyanto Hendriyawan University of Hkbp Nommensen Sutomo Street No.4A Medan20234 Indonesia Post Graduate Program Civil Engineering Departement University of Sumatera Utara Medan-North Sumatera20155 Indonesia Institute of Technology Bandung Ganesha 10 Bandung West-Java40135 Indonesia Civil Engineering Departement University of Sumatera Utara Medan North-Sumatera20155 Indonesia

The function of the basement is to carry the weight of the upper structure into the soil and to resist lateral loads around the basement wall. One aspect of geotechnical engineering that often a problem in basement wall planning is the determination of lateral ground pressure in the basement wall due to earthquake which must be held by the basement wall. In this study, an analysis of the effects of local soil conditions due to dynamic loads is done through analysis of soil-structure interaction. The analysis is done by modeling the local soil with variations in basement depth and the adjacent basement distance to get the lateral pressure distribution due to dynamic load. The analyzed soil conditions are considered homogeneous at land sites SE (soft soil) with the dynamic load input from earthquake loads uses a 10% probability of exceedance in 50 years (500 years). The most influential parameter for soil displacement is the distance of the basement and then the depth of the basement. The most influential parameter on lateral forces is the depth of the basement followed by the distance of the basement. © 2020 IOP Publishing Ltd. All rights reserved.

关键词： Dynamic loads

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Polymer concrete reinforced with luffa fibers: Effect of gamma radiation

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Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia 2014年第3期37卷 22-29页

作者： Martínez-Barrera, Gonzalo Martínez-López, Miguel Vigueras-Santiago, Enrique Gencel, Osman Beycioglu, Ahmet Dos Reis, João Marciano Laredo Facultad de Química Universidad Autónoma del Estado de México Km.12 de la carretera Toluca-Atlacomulco San Cayetano Mexico Civil Engineering Department Faculty of Engineering Bartin University Bartin Turkey Civil Engineering Department Faculty of Technology Düzce University Düzce Turkey Theoretical and Applied Mechanics Laboratory - LMTA Mechanical Engineering Post Graduate Program - PGMEC Universidade Federal Fluminense - UFF RuaPasso da Pátria 156 Bl. E sala 216 Niterói RJ Brazil

The interest of many research groups regarding manufacture of composite materials by using natural fibers is increasing world-wide. The main objectives involve the improvement of mechanical properties, mainly those related to resistance and elasticity. In the present study in a first stage, polymer concrete specimens were elaborated by using an unsaturated polyester resin, silica sand and luffa fibers; after, they were gamma irradiated at different doses and their mechanical properties were evaluated. Two different silica particle sizes (0.15 mm and 0.6 mm), and four different luffa fiber concentrations (0.3, 0.6, 0.9 and 1.2 wt%) were used, as well as 50 and 100 kGy of radiation dose. The results show a gradually diminution of compressive strength and modulus of elasticity when adding luffa fiber concentration. Nevertheless, such mechanical features are increasing when polymer concrete is gamma irradiated.

关键词： Unsaturated polymers

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Organizational Trouble Shooting through Integration between the Theory of the Restrictions Thinking Process and Lean Tools

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Journal of civil engineering and Architecture 2014年第6期8卷 738-745页

作者： Tatiana Gondim do Amaral Vitor Hugo Martins Resende Department of Post Graduate Degree Program in Geotechnical Civil Construction and Structure (PPGECON) FederalUniversity of Goidts Goidnia 74886044 Brazil Department of Engineering Catholic University of Golds Goiania 74605-220 Brazil

The theory of constraints thinking process, created by Israeli physicist Eliyahu M. Goldratt, has emerged as a tool for achieving competitive advantage. Many researches also focused on the application of lean thinking developed by Toyota and proposed by Ohno. This philosophy has been proven to be effective in several production processes. This paper aims to propose a method of problem solving through the integration of theory of constraints thinking process and the principles of lean production. As a tool for problem identification, the method defends the use of current reality tree and, to solve problems, the lean thinking tools, proposed by Picchi. The developed method was implemented in a contractor. The research methodology was research-action. Among the results, there was a realistic diagnosis about the core problems in company. According to this, the core problem of the contractor is “the lack of commitment of manpower” that results in the main problem “the financial loss”. The principle of perfection was verbalized as a proposal to solve the problems and the tools to be implemented for solving problems were “commitment of senior management to employees” and “simplicity in communication”.

关键词： Commitment people culture change agreement theory.

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