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  • 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.
1

Sensitivity of Steel Purlins to Changes in Application of Wind Loads

Douglas, Mary Keith 25 June 2020 (has links)
This project studied the effects of wind tunnel test loads applied to purlins in low rise steel buildings compared to those determined with currently recognized wind loading provisions. The National Institute of Standards and Technology (NIST) database of low-rise building wind tunnel test data, which was collected at the University of Western Ontario (UWO) boundary layer wind tunnel, was used to model a realistic wind load scenario. Pressure coefficient data recorded in the database was applied statically to individual purlins in a typical design for the size of buildings studied. These results were then compared to those obtained using the wind design provisions in ASCE 7-16 Chapter 30 for Components and Cladding. The primary data of interest was shear and moment values along the length of the purlins, which were modeled as continuous beams. Comparisons were made between the resultant shear and moment from both the wind tunnel load and ASCE 7-16 load values at 1-foot increments along the length of the purlin. The results showed that the overall peak values obtained from wind tunnel test loads were 3% to 49% higher than those calculated using ASCE 7-16 for purlins that were on the windward edge of the building. Purlins on the interior of the building varied in whether they exceeded the loads calculated with ASCE 7. Changing the height of the structure and the terrain roughness both increased the number of purlins that were lower than the values provided in ASCE 7-16 in the interior of the structure. / Master of Science / Purlins are roof members used in low rise steel buildings to transmit wind loads applied to the roof of the structure to the frame of the building. This project studied the effects of applying loads to purlins using methods specified by the code compared to those found in a wind tunnel, to look at the similarity of the values and model the actual behavior of the purlins more accurately. For this study, wind tunnel test data obtained from the National Institute of Standards and Technology (NIST) database was applied to the purlins and the shear and moment was calculated. These results were compared to the current code requirements provided in the American Society of Civil Engineers (ASCE) 7 document: Minimum Design Loads and Associated Criteria for Buildings and Other Structures. The results showed that the loads developed in the purlins subjected to wind tunnel test loadings were 3% to 49% higher on the edge of the building than those that had the ASCE 7 design loads applied. More accurately modeling the behavior of the purlins using wind tunnel test data and beam models showed that in locations where the purlins received the maximum wind force, the ASCE 7 requirements for components and cladding tended to be lower than the wind tunnel test data. However, in locations where the purlins were not experiencing the maximum wind force, the ASCE 7 requirements tended to overpredict the loads, based on the use of symmetric high wind areas to design for all wind angles.
2

Sagging and hogging strengthening of continuous reinforced concrete beams using Carbon Fiber-Reinforced Polymer Sheets

Ashour, Ashraf F., El-Refaie, S. A., Garrity, S. W. 06 March 2009 (has links)
No description available.
3

Most přes dálnici / Bridge over a highway

Vaculíková, Klára January 2015 (has links)
The diploma thesis describes the design of curved, pre-stressed concrete bridge over the highway D1. A variant, that is chosen for detail analysis, is a spine girder construction as a continuous beam with 3 spans. The thesis solves the construction to limit states according to applicable European standards (Eurocodes). There are developed clear and detailed drawings and visualization of the bridge.
4

Etude expérimentale et numérique des poutres continues en béton armé renforcées ou réparées par collage des matériaux composites / Experimental and numerical study of continuous reinforced concrete beams strengthened or repaired by bonding composite materials

Ali, Harith abdullah ali 20 October 2017 (has links)
Le renforcement en flexion des poutres de béton armé par collage externe de matériaux composites s’est révélé être une technique efficace et pratique. Cette thèse présente une étude sur la performance à la flexion des poutres continues en béton armé avec trois travées réparées ou renforcées par collage de tissus en fibres de carbone (CFRP) ou en fibres de verre (GFRP). Le programme expérimental se compose de deux groupes. Le groupe-1 est composé de huit poutres et le groupe-2 est composé de huit poutres. Dans chaque groupe, il y a une poutre de référence, poutre non renforcée. Toutes les poutres ont la même longueur de 9m et la même section de 15x25 (cm). Les essais expérimentaux avec le chargement monotone ont été effectués à l’aide d’une presse de 1000 kN. Les paramètres étudiés sont : effet du renforcement par CFRP et GFRP, épaisseur optimale du renforcement, efficacité de la réparation des poutres endommagées par CFRP et GFRP, comportement mécanique, les modes de rupture des poutres continues en béton armé renforcées. Les essais experimentaux et des calculs par la simulation numérique ont été effectués. Cinq modes de rupture des poutres ont été observés. La résistance maximale d’une poutre peut être améliorée entre 14,8 et 33,0% dans le cas des poutres renforcées par collage de CFRP et entre 7,2 et 11,8% par collage de GFRP. Il existe d’une épaisseur optimale du renforcement dans les trois portées de la poutre. La poutre complètement endommagée peut être réparée à 100%. Le moment de flexion maximal de la poutre endommagée et réparée devient supérieur à celui de la poutre de référence. Une étude numérique, à l'aide de la méthode des éléments finis en utilisant le logiciel ABAQUS, sur les poutres continues en béton armé renforcées ont été également réalisée. / The flexural strengthening of RC beams by external bonding of composite materials has proved to be an efficient and practical technique. This thesis presents a study on the flexural performance of reinforced concrete continuous beams with three spans repaired or strengthened by bonding carbon fiber reinforced polymer (CFRP) or glass fiber reinforced polymer (GFRP). The experimental program consists of two groups. Group-1 consists of eight beams and group-2 consists of eight beams. In each group, there is a reference beam, unreinforced beam. All beams have the same length of 9m and the same section of 15x25 (cm). The experimental tests with the monotonic loading were carried out using a 1000 kN press. The parameters studied are effect of reinforcement by CFRP and GFRP, the optimum thickness of the strengthening, repair efficiency of the beams damaged by CFRP and GFRP, mechanical behavior, the rupture modes of strengthened reinforced concrete beams. Experimental tests and calculations by numerical simulation were carried out. Five modes of the breaking of the beams were observed. The maximum strength of a beam can be improved by 14.8 and 33.0% for beams reinforced by CFRP bonding and between 7.2 and 11.8% by bonding GFRP. There is an optimum thickness of the reinforcement in the three spans of the beam. The fully damaged beam can be repaired at 100%. The maximum bending moment of the damaged and repaired beam becomes greater than that of the reference beam. A numerical study, using the finite element method with the help of ABAQUS software, on strengthening the continuous concrete beams, was also carried out.
5

Most přes Lochkovské údolí / Bridge across the Lochkov Valley

Zvolánek, Lukáš January 2013 (has links)
The theme of the Master’s thesis is detailed design of superstructure for selected option of the bridge. The bridge carries highway across Lochkov valley. The superstructure, 6 spans, is made of one cell continuous box beam with large overhangs supported by prefabricated struts. The continuous beam is in plan curvature. As the first, side spans 1, 5, 6 will be casting on fixed scaffolding. Spans 2 and 4 will be casting using cantilever method, gradually hanging superstructure up. For the casting the main span will also be using cantilever method, gradually removing temporary hangers of adjacent spans. The structure was analysed according to limit states. The thesis also includes a time dependent analysis of the structure and solution of influence construction on its design.
6

Dálniční most přes silnici II/464 / Highway bridge ower the II/464 road

Zalubel, Tomáš January 2014 (has links)
The master´s thesis is about detailed design of highway bridge from prestressed concrete between the cities Brno and Ostrava. The construction is continuous and consists from three fields. Internal forces was taken from software SCIA Engineer. The static assessment was realized according to limit states. Counstruction is evaluated according to the current standards.
7

Most na rampě / Bridge on a ramp

Páteček, Tomáš January 2015 (has links)
The object of this diploma thesis is the design and review of a bridge on a ramp. The bridge is part of a junction between the expressway R35 and the highway D1. Three case studies were made. The bridge construction is solved as continuous beam with six spans. The resulting design was made of prestressed concrete according to valid standards. The gradual construction was taken into consideration.
8

Most na obchvatu Banské Bystrice / Bridge on Banská Bystrica by-pass road

Nemrava, Jiří January 2012 (has links)
The theme of the master’s thesis is detailed design bridge structure. The thesis is devoted to limit states assessment of the structure. The thesis includes a time analysis structure and a detailed solution influence of construction on its proposal.
9

Mostní provizórium pro pěší a cyklistickou dopravu z materiálů vyšších pevností / Temporary bridge for pedestrian and cycling transport from high strength material

Bártů, Adam January 2020 (has links)
The purpose of the thesis is to suggest a span enlargement of steel Modular footbridge ML36 for pedestrian and cycling transport. The aim is to preserve as many elements of the original construction as possible. In the thesis, three variants are discussed with the detailed focus on one of them. The chosen variant is made up by elongated original footbridge ML36, which is supported by prestressed structure. From the static point of view, it is a simply supported truss. The span of the footbridge is 39-45. The main material of the structural elements is steel S355, S460 and S520.
10

Most na rampě v Brně / Bridge on a ramp in Brno

Vančura, Lukáš January 2014 (has links)
The topic of the thesis is the design and assessment of roadway bridge structure, which is curved in the horizontal plan with a very small radius. Bridges is part of the flyover crossing in Brno. There are designed two variations of which are further developed the variant of the two-chamber cross-section. Calculations and assessments are conducted in according to the valid European standards (Eurocodes). The static calculation is supplemented with a clear technical drawings and visualizations.

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