• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 159
  • 40
  • 14
  • 10
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 238
  • 238
  • 152
  • 151
  • 69
  • 52
  • 49
  • 47
  • 47
  • 45
  • 42
  • 39
  • 38
  • 37
  • 36
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Lávka přes kolejiště / The footbridge across the track

Mojžíš, Jan January 2013 (has links)
This thesis describes the design of steel structures footbridge over the track in Havířov. The total length of the bridge is 101.6 m footbridge consists of four parts. The basic structural system of the first part of the beam is solidified arc. Other parts are made girders. Free bridge width is 3.2 m Footbridge will be used to connect local area Havířov - Šumbark to the train station.
12

Effects of Member Overstrength and Initial Residual Stresses on the Behaviour of 2D Steel Structure

Lu, Yen-Cheng (Arthur) January 2011 (has links)
Extended Direct Analysis (EDA), developed at the University of Canterbury, is an advance on the AISC Direct Analysis method for the analysis of frames subjected to static forces. EDA provides a faster, simple and more rational way to properly consider the second-order effects, initial residual stresses (IRS) and the initial imperfections or steel structures under one directional loading than conventional analysis methods. This research applied the EDA method to quantify the effect of member overstrength on frame behaviour for a single storey frame. Also, the effects of IRS, which were included in the EDA static analysis, but which are not considered explicitly in non-linear seismic analysis, were evaluated in two ways. Firstly, they were considered for simple structures subject to increasing cyclic displacement in different directions. Secondly, incremental dynamic analysis with realistic ground motion was used to quantify the likely effect of IRS in earthquakes. It was found that, contrary to traditional wisdom and practice, greater member strengths can result in lower frame strengths for frames under monotonic lateral loading. The structural lateral capacity of the overstrength case was reduced by 6% compared to the case using the dependable member strengths. Also, it resulted significantly different in member demands. Therefore, it is recommended that when either plastic analysis or EDA is used, that both upper and lower bounds on the likely member strength should be considered to determine the total frame strength and the member demands. Results of push-pull analysis under displacement control showed that for IRS ratio, gamma < 0.5 and axial compressive force ratio, N*/Ns, up to 0.5, IRS did affect the structural behaviour in the first half cycle. However, the behavior in the later cycles was not significantly affected. It also showed that the effect of initial residual stresses in the frame was less significant than for the column alone when the column was subjected to similar axial compressive force. The incremental dynamic analysis results from both cantilever column and the three-storey steel frame showed that by increasing gamma = 0 to 0.5, the effect of IRS on seismic responses, based on the 50% confidence level, was less than 3% for N*/Ns, up to 0.5.
13

Unmanned Aerial Vehicle Remote Sensing Technology for Structural Damage Assessments in Low-Light Conditions

Christopher A Baker (7041473) 12 August 2019 (has links)
The research explores the viability of using a small Unmanned Aerial Vehicle equipped with thermal imaging and lowlight camera to assess structural damage to steel girders. Damage assessments following natural disasters are daunting and arduous tasks that are resources intensive and dangerous. Unmanned aerial vehicles with remote sensing technology (UAV-RS) have been used in recent large-scale disaster events such as Hurricanes Katerina, Harvey, Irma, and Maria as well as others. Current assessment methods of structures include; inspectors physically conducting detailed and rapid surveys of damage with or without the assistance of special equipment, use of helicopters, satellite imagery, and new innovative methods using unmanned aerial vehicles with remote sensing technology. <div><br></div><div>The initial experiment utilized the S-BRITE facility at Purdue University. Two steel girders located at S-BRITE were used in the experiment with damages that render them structurally deficient. Experiments were conducted during hours of low visibility.</div><div><br></div><div>Most scientific studies have focused on using UAV-RS during hours of daylight. This research exploresthe use of UAV-RS during low-light conditions (i.e. early evening nautical and astronomical twilight, and night) for detecting global damage to steel girders. The goal is to present evidence for further study in the use of UAV-RS during low-light conditions for inspecting structures to include primary load bearing members. The research concluded that while the UAV-RS can detect global damage in low visibility conditions, further experiments in varying low-light conditions to include3D imaging and semi-autonomous inspectionusing computer vision are important for structural damage assessments.</div>
14

Produtividade na montagem de estruturas de aço para edifícios. / Productivity of steel structures erection for building.

Mingione, Caio Marranghello 23 February 2016 (has links)
A busca por melhorias de produtividade na indústria da construção civil é fundamental para garantia do crescimento sustentável do setor. Nesse sentido, o uso de estruturas de aço na construção de edifícios aparece como uma alternativa interessante às tradicionais estruturas em concreto armado. Essa dissertação tem por objetivo o estudo da produtividade da mão de obra e de equipamentos de içamento na montagem de estruturas de aço para edifícios de múltiplos pavimentos, buscando comprovar a hipótese de que essa produtividade varia em conjunto com alguns fatores que podem ser identificados e que essa variação pode ser quantificada. A pesquisa foi realizada segundo metodologia de Estudo de Caso, sendo que cinco obras compuseram o estudo. Como resultados, observa-se que produtividade potencial da mão de obra variou entre 3,33 e 8,23 Hh/peça ou 11,8 e 33,8 Hh/t e que a produtividade potencial dos equipamentos variou entre 0,38 e 0,53 Eqh/peça ou 1,84 e 2,29 Eqh/t, além de terem se encontrado correlações significativas entre os fatores tonelada/peça, disponibilidade do equipamento de içamento e quantidade relativa de pilares e os indicadores de produtividade. / The search for productivity gains in the construction industry is critical to ensure the sustainable growth of the sector. The use of steel structures for buildings appears as an interesting alternative to the traditional concrete structures. This research aims to study labor productivity and lifting equipments productivity in the erection of steel structures for multistory buildings, trying to prove the hypothesis that productivity indicators are correlated with some identifiable factors and that its variation can be quantified. The research was conducted as a Case Study, in which five construction sites were considered. As a result, it was observed that labor productivity ranged between 3,33 and 8,23 man-hour/piece or 11,8 and 33,8 man-hour/t, and that the equipments productivity ranged between 0,38 and 0,53 equipment-hour/piece or 1,84 and 2,29 equipment-hour/t, and it was found significant correlations between the factors tons per piece, equipment availability and relative number of columns and the productivity indicators.
15

Analysis Of Blast Loading Effect On Regular Steel Building Structures

Tahmilci, Fatih 01 December 2007 (has links) (PDF)
Concern about effect of explosives effect on engineering structures evolved after the damage of Second World War. Beginning from 90&rsquo / s with the event of bombing Alfred P. Murrah Federal building located in Oklahoma City this concern deepened and with the attack to World Trade Center twin towers on September 11, 2001 it is peaked. Recent design codes mainly focus on earthquake resistant design and strengthening of the structures. These code design methodologies may sometimes satisfy current blast resistant design philosophy, but in general code compliant designs may not provide recognizable resistance to blast effect. Therefore designer should carry out earthquake resistant design with the blast resistant design knowledge in mind in order to be able to select the most suitable framing scheme that provide both earthquake and blast resistance. This is only possible if designer deeply understands and interprets the blast phenomenon. In this study, it is intended to introduce blast phenomenon, basic terminology, past studies, blast loading on structures, blast structure interaction, analysis methodologies for blast effect and analysis for blast induced progressive and disproportionate collapse. Final focus is made on a case study that is carried out to determine whether a regular steel structures already designed according to Turkish Earthquake Code 2007 requirements satisfy blast, thus progressive collapse resistance requirements or not.
16

Toyota Just In Time Production System Application In Steel Structure Industry-China Steel Structure Coperation

Lee, Chien-Cheng 21 May 2003 (has links)
There has been full of inefficiency and waste in current operation method of steel structure industries. This study hopes to utilize Toyota Just-in-time Production System for fabrication of steel structure to eliminate current each waste during the production process. The main purpose of this study is take case company as an example to discuss the following respects: 1.The current production process of steel structure industries. 2.The application of Toyota Just-in-time Production System in the steel structure fabrication. This study first introduces the framework of Toyota Just-in-time Production System to apprehend its spirit and then explains the concept and advantage of Toyota Just-in-time Production System explicitly. Also, this study compares Toyota Just-in-time Production System with current production method of steel structure industries. Second, according to the glancing of related document reference, this study discusses the application method and its profit for Toyota Just-in-time Production System in the manufacturing industries. As there are significant differences in structure or operation method between steel structure industries and manufacturing industries, thus this study utilizes gradual erection plan to match Toyota Just-in-time Production System during the period of fabrication process plan to eliminate the distinction between these two industries besides explaining the necessary rationalized operation when leading Toyota Just-in-time Production System in. Having visited the production line and made mutual communication with operation chief, this study has found the current problems existing in production management in case company. According to this discovery, this study uses bridge production line and built-up H section production line as pilot implementation to discuss the possible question and solution policy for Toyota Just-in-time Production System concept applied in steel structure fabrication so as to frame the procedures and criterion of Toyota Just-in-time Production System in fabrication of steel structure and also to evaluate its profit.
17

Study on Architecture-Oriented Steel Structure Material Scheduling Model

Sun, Chin-i 04 July 2008 (has links)
Steel structure enterprises, belonging to domestic-oriented industry, are capital intensive and skill intensive as well. The ability of huge fund deployment and excellent project management is the key for such kind of enterprises to survive in the competitive environment due to the low entry barrier and little profit margin. The cost of the material accounts for the most, usually the greatest proportion of the total contract, in an entire steel structure project. Therefore, the profit in general depends heavily on the quality of material management. In this thesis, we propose Architecture Oriented Steel Structure Material Scheduling Model (AOSSMSM), to capture the current material inventory, reduce the remaining stock, improve the circulation and substitutability, and increase the profit. AOSSMSM constructs system architecture which includes enterprise architecture and software architecture, therefore highlights material¡¦s service and interaction among culture value chain in enterprise and integrates with information application system. By duplication and expansion characteristics of system architecture, AOSSMSM can be replicated effortlessly by other steel structure companies, or bridged to other models to create a new operational formation.
18

DETERIORATION CHARACTERISTICS OF Sn-BEARING STEEL BY ACCELERATED EXPOSURE TESTS

ITOH, Y., KAMIMURA, T., HIROHATA, M., MORI, T. 09 1900 (has links)
The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction, September 11-13, 2013, Sapporo, Japan (EASEC-13)
19

Dimensionamento de silos metálicos para armazenagem de grãos / Design of steel silos for grain storage

Scalabrin, Luciano Argenta January 2008 (has links)
Neste trabalho, apresentam-se as formas mais comuns de acidentes em silos buscando explicar as causas que ocasionaram o colapso. Trata-se de analisar a teoria e as recomendações de duas das principais normas para a determinação das pressões devidas aos grãos armazenados no interior do silo. Desenvolvem-se planilhas de cálculo para auxiliar o dimensionamento de um silo. Busca-se maximizar a força de tração admissível para cada espessura de chapa lateral com o intuito de obter silos mais leves e conseqüentemente mais econômicos. Da mesma forma, uma planilha de cálculo é apresentada para maximizar a força de compressão para diferentes espessuras de montantes. Um configurador de silo é apresentado no decorrer do trabalho, tendo como dados de entrada o diâmetro e altura do silo e obtendo as diferentes espessuras de chapa laterais com relação à altura bem como os diferentes montantes. Apresentam-se formas de análise de silos, quando vazios, submetidos à carga de vento e a necessidade de colocação de anéis de reforço na circunferência e sua distribuição na altura. Trata-se de analisar o efeito de silos quando vazios pelo método dos elementos finitos, levando em consideração a rigidez da chapa lateral. / In this work, some accidents in silos are presented and the causes are discussed. The theory and the recommendations of two standards for determination of pressure due to grain stored inside the silo are presented. Sheets for silos design are developed. The goal is to maximize the tension force in the silos lateral sheet for each thickness, in order to improve economical benefits. Similarly, another sheet is developed with the goal to maximize the compression force in the stiffeners for different thicknesses. A design sheet for silos is presented in the course of the work; diameter and height of the silo are the input data and different thicknesses of lateral sheet and stiffeners are output data. Different approach for empty silos considering wind loads are presented and the use of wind-rings are verified. Empty silos are examined by the finite elements method considering lateral rigidity of the lateral sheet.
20

Dimensionamento de silos metálicos para armazenagem de grãos / Design of steel silos for grain storage

Scalabrin, Luciano Argenta January 2008 (has links)
Neste trabalho, apresentam-se as formas mais comuns de acidentes em silos buscando explicar as causas que ocasionaram o colapso. Trata-se de analisar a teoria e as recomendações de duas das principais normas para a determinação das pressões devidas aos grãos armazenados no interior do silo. Desenvolvem-se planilhas de cálculo para auxiliar o dimensionamento de um silo. Busca-se maximizar a força de tração admissível para cada espessura de chapa lateral com o intuito de obter silos mais leves e conseqüentemente mais econômicos. Da mesma forma, uma planilha de cálculo é apresentada para maximizar a força de compressão para diferentes espessuras de montantes. Um configurador de silo é apresentado no decorrer do trabalho, tendo como dados de entrada o diâmetro e altura do silo e obtendo as diferentes espessuras de chapa laterais com relação à altura bem como os diferentes montantes. Apresentam-se formas de análise de silos, quando vazios, submetidos à carga de vento e a necessidade de colocação de anéis de reforço na circunferência e sua distribuição na altura. Trata-se de analisar o efeito de silos quando vazios pelo método dos elementos finitos, levando em consideração a rigidez da chapa lateral. / In this work, some accidents in silos are presented and the causes are discussed. The theory and the recommendations of two standards for determination of pressure due to grain stored inside the silo are presented. Sheets for silos design are developed. The goal is to maximize the tension force in the silos lateral sheet for each thickness, in order to improve economical benefits. Similarly, another sheet is developed with the goal to maximize the compression force in the stiffeners for different thicknesses. A design sheet for silos is presented in the course of the work; diameter and height of the silo are the input data and different thicknesses of lateral sheet and stiffeners are output data. Different approach for empty silos considering wind loads are presented and the use of wind-rings are verified. Empty silos are examined by the finite elements method considering lateral rigidity of the lateral sheet.

Page generated in 0.0717 seconds