检索结果-内蒙古大学图书馆

9th International Conference on Computational Structures Technology, CST 2008

作者： Da Silva, J.G.S. Da S. Vellasco, P.C.G. De Andrade, S.A.L. De Lima, L.R.O. De Almeida, R.R. Mechanical Engineering Department State University of Rio de Janeiro - UERJ Brazil Structural Engineering Department State University of Rio de Janeiro - UERJ Brazil Civil Engineering Post-Graduate Programme - PGECIV State University of Rio de Janeiro - UERJ Brazil

ISBN: (纸本)9781905088232

This paper investigated the dynamic behaviour of long span joist floors subjected to the human rhythmic activities. The dynamic loads were obtained through experimental tests with individuals carrying out rhythmic and non-rhythmic activities. The proposed analysis methodology adopted the usual mesh refinement techniques present in the finite element method simulations. Based on the experimental results, human load functions due to rhythmic and non-rhythmic activities were proposed. The investigated structural system was a typical floor used as a restaurant with an adjacent dancing area. The composite (steel-concrete) floor system consisted of long span (14m) joists supported by concrete block walls. The peak acceleration values were compared to the limits present in design recommendations, based on human comfort criteria. The results indicated that the limits suggested by design recommendations were not satisfied. Such fact indicated that these rhythmic activities could generate peak accelerations that surpass design criteria limits developed for ensuring human comfort. © civil-Comp Press, 2008.

关键词： Structural dynamics

来源：评论

学校读者我要写书评

暂无评论

Numerical evaluation of stainless steel joints subject ot tension

Numerical evaluation of stainless steel joints subject ot te...

引用

12th International Conference on civil, Structural and Environmental engineering Computing, CC 2009

作者： Da Silva, A.T. Santos, J. De J. Dos De Lima, L.R.O. Vellasco, P.C.G. Da S. De Andrade, S.A.L. Da Silva, J.G.C.S. PGECIV Post-Gradutaete Program in Civil Engineering State University of Rio de Janeiro UERJ Brazil Structural Engineering Department State University of Rio de Janeiro UERJ Brazil Mechanical Engineering Department State University of Rio de Janeiro UERJ Brazil

ISBN: (纸本)9781905088300

The use of stainless steel in structural engineering applications is still seen by a number of architects and engineers as an extravagant solution. However, attitude changes towards a sustainable development environment have boosted the stainless steel structures use. Despite theses facts, a substantial majority of stainless steel structural design codes is still based on carbon steel analogies. At this point it is interesting to observe the stainless steel presents four non-linear tension versus strain curves (tension and compression, parallel and perpendicular to the rolling direction) without a defined yield plateau and strain hardening zones, characteristics that substantially alters its global structural response. The present investigation adopted the austenitic stainless steel grade 304 and the carbon steel USI300, both with similar yield stresses, but with different tension stresses and ductility capacities. Structural elements subjected to tension axial forces usually presents the net section rupture as one of its controlling ultimate limit states. The present paper describes a numerical model developed to evaluate and investigate the tension capacity of staggered bolted members calibrating their results with an innovative experimental programme. The experiments were made with carbon and stainless steels to compare and access their similarities and differences in terms of structural performance. The controlling ultimate limit states were significantly influenced by various parameters like: the loading plate thickness, layout, configuration and number of adopted joint bolts, and stainless steel properties like ductility capacity and the ratio between yield to rupture tension stresses. © civil-Comp Press, 2009.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Application of the Updated PSHA on the Stability Analysis of the Meninting Diversion-Spillway Tunnel in Lombok Island—Indonesia 5th

Application of the Updated PSHA on the Stability Analysis of...

引用

5th International Conference on Rehabilitation and Maintenance in civil engineering, ICRMCE 2021

作者： Agustawijaya, Didi S. Marlaningtyas, Ria R. Murtiadi, Suryawan Wahyudi, Mudji Muhajirah Hartana Agustawijaya, Ausa R. Post-Graduate Study Program Department of Civil Engineering University of Mataram Mataram Indonesia Geo-Engineering Research Group Department of Civil Engineering University of Mataram Mataram Indonesia Department of Geomatics Engineering ITS Surabaya Indonesia

ISBN: (纸本)9789811693472

The Meninting diversion-spillway tunnel is a part of the Meninting dam project located in West Lombok District. The construction commenced in 2017;then, a series of severe Lombok earthquakes halted the construction of the tunnel for a while in 2018, where some landslides occurred around the site. This possibly caused rock masses around the tunnel to be sheared off during the earthquake events. Updated probability seismic hazard analysis shows increased seismic parameters, including peak ground, short spectrum and long spectrum accelerations, which then resulted in increased stresses around the tunnel. Thus, the stability of the tunnel decreased in terms of its factors of safety. Although, the overall factor of safety was about 2.5, the tunnel was still stable in current conditions;the tunnel certainly requires more stability improvements to face possible similar severe earthquakes in future. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Earthquakes

来源：评论

学校读者我要写书评

暂无评论

Selection of sensitive features for damage identification in a railway bridge

Selection of sensitive features for damage identification in...

引用

作者： Meixedo, A. Alves, V. Ribeiro, D. Calçada, R. Faculty of Engineering University of Porto Portugal Post-Graduate Program in Civil Engineering Federal University of Ouro Preto Brazil School of Engineering Polytechnic of Porto Portugal

This paper aims selects sensitive features for damage identification in a railway bridge. For this purpose, a damage identification methodology based on a genetic algorithm and its application to the numerical model of a railway bridge is proposed. The identification method is based on an iterative process that in each iteration compares the values of the dynamic responses of a bridge for a test damage scenario with the response values for a reference damage scenario. The introduction of damage in the test numerical model is based on the modification of preselected numerical parameters 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 damage indicators. In this study damage indicators, based on the deck accelerations of the bridge subject to the action of the Alfa Pendular train defined as a set of moving loads, are defined and tested. The proposed methodology for identifying damage has been tested using a two-dimensional numerical finite element model of a railway bridge including the railway track. The results enabled the evaluation of the efficiency and reliability of the methodology and of the damage indicators which, in most situations, showed potential for the detection, location and quantification of the severity of the damage. © civil-Comp Press, 2016.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

12.06: Numerical analysis of stainless steel, concrete encased and carbon steel double skin tubular stub columns

引用

ce/papers 2017年第2-3期1卷 3509-3518页

作者： de Araújo, Raphaella Oliveira de Lima, Luciano Rodrigues Ornelas da Silva Vellasco, Pedro Colmar Gonçalves da Silva, André Tenchini PGECIV – Civil Engineering Post-Graduate Program State of Rio de Janeiro – UERJ Brazil Structural Engineering Department State University of Rio de Janeiro – UERJ Brazil

The use of stainless steel as formwork for concrete columns provides several benefits for the structure, including the high corrosion resistance, durability, fire resistance, ease of maintenance and high aesthetic value. The use of composite systems in columns has been a major breakthrough in bridges and viaducts. A particular advantage of the composite columns is the reduction of cross sectional area, speed of construction, easy maintenance and material saving when compared to conventional reinforced concrete structures. These advantages are related to the idea that the columns are concrete filled eliminating the use of forms and the need for extra steel reinforcing bars. The investigated system adopts a second carbon steel tube inside the primary stainless steel tube composing the structural system made of concrete-filled double skin composite tube columns (CFDSCT). This study aims to develop numerical models, using the finite element method and considering geometric imperfections. The structural behaviour was assessed through a nonlinear analysis and was later compared to compressive tests performed in the laboratory. After the completion of the numerical models calibration, a parametric analysis was performed to investigate the influence of parameters like the diameter, thickness and height of the stainless steel tube (outer) while its results were also compared to predictions made by traditional design equations. © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Stainless steel

来源：评论

学校读者我要写书评

暂无评论

Structural performance of stainless lap bolted joints

引用

ce/papers 2017年第2-3期1卷 3593-3602页

作者： Freire, Raphael da Silva Vellasco, Pedro Colmar Gonçalves da Silva, André Tenchini de Lima, Luciano Rodrigues Ornelas PGECIV – Civil Engineering Post-Graduate Program State of Rio de Janeiro – UERJ Brazil Structural Engineering Department State University of Rio de Janeiro – UERJ Brazil

The stainless steel employed in the structural elements present high corrosion resistance, durability, fire resistance and high aesthetic value compared to those constructed using carbon steel. In contrast, the stainless steel structures design is made following the requirements based on the carbon steel analogies. In fact, the structural performance of stainless steel is complex and dissimilar where some stainless grades presenting nonlinear tension versus strain curves without a defined yield plateau and large strain hardening. These properties influence on structural performance of the lap bolted joints. The Eurocode 3 pt. 1.4, one of the most adopted design codes, recommends two structural design criteria for the stainless steel elements under tension: ultimate resistance of the net cross-section at holes or plastic resistance of the gross cross-section. The present work aimed to investigate the structural response of lap bolted joints made of three stainless steel grades: austenitic, ferritic and duplex. Nonlinear numerical analyses has been carried out using ABAQUS 6.14 program where the response have shown a good agreement in terms of the maximum loads and failure modes when compared to the performed experiments. The results indicated a conservative level of safety from Eurocode 3 pt. 1.4 code provisions in comparison to the experimental results. © 2017 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Finite Element Modelling of Steel Beams with Web Openings

引用

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

来源：评论

学校读者我要写书评

暂无评论

Determination of time zero in high strength concrete containing superabsorbent polymer and nano-silica

引用

Journal of Building Pathology and Rehabilitation 2016年第1期1卷 1-12页

作者： Cunha, T.A. Francinete, P. Manzano, M.A. Aidar, L.A. Borges, J.G. Silva, E.F. Post-Graduate Program in Structures and Civil Construction (PECC/UnB) University of Brasília Brasília Federal District Brazil Civil Engineering Department (ENC/UnB) University of Brasília Brasília Federal District Brazil

The autogenous shrinkage is a phenomenon that occurs due to the appearance of tensile stresses in capillary pores. Inherent in the hydration process, not depending on external interference. In high strength concrete, autogenous shrinkage is most pronounced, due to the refinement of microstructure, the high cement content, presence of mineral addictions and low water/cement ratio, which interfere in the transport of water curing. In this context, Superabsorbent polymers (SAP) stand out for their ability to reduce or eliminate the autogenous shrinkage, because they absorb large amounts of water, which is subsequently released into the matrix, avoiding self-desiccation and the onset of tensile stresses (internal curing). However, studies show that SAP can reduce the mechanical strength, which can be compensated by addiction of Nano-silica (NS). In this paper, the effect of these additions in Time Zero (T₀) was evaluated. T₀ determines the time at which the material starts to behave as a solid, with the development of a rigid mineral skeleton to oppose the volumetric variations that occurs in the paste, which can lead to cracking, compromising esthetics, durability, and structures safety. The ultrasonic pulse velocity test performed the T₀, which measures the velocity of propagation of an ultrasonic wave through the material and is taken as the time when a sudden change occurs at this velocity. Nine blends were made containing SAP and NS, where it was found that SAP addition increases the T₀ (up to 11%), while NS decrease its value (in 55%). © 2016, Springer International Publishing Switzerland.

关键词： High performance concrete High strength concrete Nano-silica Superabsorbent polymer Time zero Ultrasonic pulse velocity

来源：评论

学校读者我要写书评

暂无评论

Fiber reinforced polymers for historical bridges upgrading: a fatigue life assessment

引用

Journal of Building Pathology and Rehabilitation 2023年第1期8卷 1-11页

作者： Garcez, Mônica Regina Meneghetti, Leila Cristina Post-Graduate Program in Civil Engineering: Construction and Infrastructure Federal University of Rio Grande do Sul Porto Alegre Brazil Department of Structural and Geotechnical Engineering University of São Paulo São Paulo Brazil

Upgrading historical structures is one of the most interesting applications of fiber reinforced polymers in construction. Historical bridges are frequently post-strengthened to increase load carrying capacity of structural elements, aiming to bear heavier commercial traffic. Fatigue life becomes crucial since the lack of available fatigue models leads to superficial analysis considering the same S–N curves for different strengthening systems and steel stress ranges. This paper uses an extensive database with experimental data from the literature to adjust linear regression models to characterize the large scatter between the results of fatigue tests from different sources. Distinct fatigue models have been developed considering three categories: externally bonded reinforcement with strips/sheets and new surface-mounted reinforcement. The different declivities found for the adjusted fatigue life models accurately represent the fatigue behavior of the post-strengthened structural elements with the assessed systems and techniques. The results support design decisions to avoid future unnecessary interventions. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

关键词： Fatigue life Fiber reinforced polymers Historical bridges Linear regression analysis

来源：评论

学校读者我要写书评

暂无评论

Identification of spatial potential flood-prone area using topographic wetness index under the digital elevation model of Kr. Keureuto watershed, North Aceh. 5

Identification of spatial potential flood-prone area using t...

引用

5th Aceh International Symposium on civil engineering 2024, AISCE 2024

作者： Rizalihadi, Maimun Meilianda, Ella Yulianur, Alfiansyah Away, Yuwaldi Doctoral Program Post Graduate Program Syiah Kuala University Banda Aceh Indonesia Civil Engineering Department Syiah Kuala University Banda Aceh Indonesia Electro and Computer Engineering Department Syiah Kuala University Banda Aceh Indonesia

Floods are the most frequent disaster events in Lhoksukon, resulting in significant losses and community and environmental damage. Floods are generated by several factors, consisting of hydrometeorological, topographical, geological, soil, and human activities. Topography is a key controlling factor in flood initiation. Topographic analysis for detecting flood susceptibility, especially flood inundation, can be conducted using the TWI. The research aims to identify the potential spatial distribution of flood-prone areas based on TWI and assess the model accuracy using the ROC-AUC method. A case study was conducted in the Kr. Keureuto watershed. of North Aceh. TWI analysis is based on the topography of an area denoted by extracting DEM using GIS to create slope, flow direction, and flow accumulation. Higher TWI values are associated with higher flood susceptibility. The results show that the value of TWI is approximately 1.571-27.147, showing that more than 20% of area are potentially flood inundations with high and very hight rating of flood susceptibility. Furthermore, based on the analysis using field observation flood is obtained the AUC value of 71,60%. It can be concluded that the spatial model of flood-prone using TWI is good and effective for determining flood prone region in the Kr. Keureuto River basin © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Watersheds

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：