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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

Holes in Glulam Beams - Possible Methods of Reinforcement

Uthman, Rawa, Othman, Rawaz January 2009 (has links)
This thesis deals with glued laminated beams with holes. Different hole geometries, circular and quadratic,  and reinforcement methods were investigated. A total of 24 tests were performed using two types of reinforcements (glass fiber and plywood) and testing unreinforced beam. During testing of the beams without reinforcement a contact free deformation measurement system was used to capture the deformation pattern. A commercial finite element software package was used to perform numerical calculations of the response of the beams. The FE-analyses were also compared with the experimental results. The test results showed that the reinforcement with plywood was more efficient than the reinforcement with glass fiber. In addition, the two hole geometries showed different failure behaviors. The beams with quadratic holes showed a less brittle behavior, although at a lower load level than the beams with circular holes. / Denna rapport behandlar limträbalkar med hål. Olika hålgeometrier, cirkulära och kvadratiska hål, och olika metoder att förstärka balkarna vid hålet undersöktes. Totalt 24 enskilda provningar genomfördes med två olika förstärkningsmetoder (glasfiber och plywood) samt med balkar utan förstärkning. Vid provning av de oförstärkta balkarna användes ett system för beröringsfri deformationsmätning för att få en bild av deformationsmönstret. Ett kommersiellt finita elementprogram användes också för att analysera balkarnas respons och för att jämföra med provningsresultaten. Provningarna visade att förstärkningen med plywood var effektivare än förstärkningen med glasfiber. Vidare uppvisade de olika hålgeometrierna olika brottbeteenden, där de kvadratiska hålen gav mindre spröda brott, dock vid en i genomsnitt lägre brottlast än de cirkulära hålen.
2

Holes in Glulam Beams - Possible Methods of Reinforcement

Uthman, Rawa, Othman, Rawaz January 2009 (has links)
<p>This thesis deals with glued laminated beams with holes. Different hole geometries, circular and quadratic,  and reinforcement methods were investigated. A total of 24 tests were performed using two types of reinforcements (glass fiber and plywood) and testing unreinforced beam. During testing of the beams without reinforcement a contact free deformation measurement system was used to capture the deformation pattern. A commercial finite element software package was used to perform numerical calculations of the response of the beams. The FE-analyses were also compared with the experimental results. The test results showed that the reinforcement with plywood was more efficient than the reinforcement with glass fiber. In addition, the two hole geometries showed different failure behaviors. The beams with quadratic holes showed a less brittle behavior, although at a lower load level than the beams with circular holes.</p> / <p> </p><p>Denna rapport behandlar limträbalkar med hål. Olika hålgeometrier, cirkulära och kvadratiska hål, och olika metoder att förstärka balkarna vid hålet undersöktes. Totalt 24 enskilda provningar genomfördes med två olika förstärkningsmetoder (glasfiber och plywood) samt med balkar utan förstärkning. Vid provning av de oförstärkta balkarna användes ett system för beröringsfri deformationsmätning för att få en bild av deformationsmönstret. Ett kommersiellt finita elementprogram användes också för att analysera balkarnas respons och för att jämföra med provningsresultaten. Provningarna visade att förstärkningen med plywood var effektivare än förstärkningen med glasfiber. Vidare uppvisade de olika hålgeometrierna olika brottbeteenden, där de kvadratiska hålen gav mindre spröda brott, dock vid en i genomsnitt lägre brottlast än de cirkulära hålen.</p>
3

Prestressed glue laminated beams reinforced with steel plates : Comparison between prestressed, reinforced and non-reinforced glue laminated beams according to the Eurocode and the Swedish annex / Förspända limträbalkar, förstärka med stålplattor : Jämförelse mellan förspända, armerade och omodifierade limträbalkar enligt Eurocode med tillhörande svenska annexet

Al-Djaber, Jafar January 2018 (has links)
The paper presents details of a numerical analysis and simplified construction of strengthened glue laminated beams. Glue laminated beams are strengthened through the use of steel reinforcements embedded between the lamellas of the beams. The study compares the numerical results from reinforced and prestressed beams, simply reinforced beams and non-modified beams. Parametric studies were undertaken to evaluate the effects on reinforcement thickness, beam span, prestressing force and prestressing loss. Modified and prestressed beams with wide spans and large dimensions had a significantly higher design load compared to non-modified beams with similar geometry and span. In the most beneficial cases, a load increase of 438% was observed for point load at midspan and 346% for uniformly distributed load.
4

LIMTRÄBALKAR SOM SUBSTITUT FÖR BETONG : En undersökning av limträbalkars substitutionseffekter sett till CO2 i atmosfären. / GLULAM BEAMS AS SUBSTITUTE FOR CONCRETE : A survey on the substitution effects of glulam beams in relation to carbondioxide in the atmosphere.

Brännlund, Alexina January 2020 (has links)
Today, a lot of resources are put into researching technological solutions concerning “carbon neutral” displacement materials and products, with the common goal of mitigating the amount of carbon dioxide in the atmosphere. The aim of this study was to find out whether a displacement of concrete to glulam beams, in the construction industry, could create substitution effects that reduces the amount of carbon dioxide in the atmosphere. To go about this, interviews were conducted with one producer of glulam beams, four construction companies and a non-profit foundation that funds research in fire prevention. Furthermore, sustainability declarations of glulam beams from three glulam beam producers, were analyzed. To compare carbon dioxide emissions in different scenarios, the interview results, as well as the sustainability declarations of the glulam beam producers, were compared and examined. Calculations of carbon dioxide sequestered in glulam beams and emitted from the concrete industry in Sweden were also regarded. The results showed that the possible substitution effects derived from a displacement of concrete to glulam beams, would have a small mitigating impact on the amount of CO2 in the atmosphere. However, recent findings point out that the pay back period for harvested trees, is longer than assumed. Moreover, the concrete production is not decreasing, but increasing. In respect of Jevons’ paradox (which concludes that higher efficiency in production leads to more consumption, not less), the conclusion of this study, was that no substitution will mitigate enough CO2 in the atmosphere. Our approach to consumption is what must change.
5

Kolfiberförstärkning av limträbalkar : Fuktens inverkan på förstärkningen

Bergström, Viktor, Tölli, Emil January 2019 (has links)
The point with this exam-essay is to study how the strength in glulam beams reinforced with carbon fiber will differentiate with an increased relative humidity (RH). The literature study brings up older work and science in the field that focuses on different reinforcement that can improve the strength in glulam beams.Glulam has higher strength than regular wood, this is due to how glulam is being constructed. When the usage limit condition is being determined the length of the beam will be a factor in deciding highest allowed bending on the beam. Carbon fiber, that has a greater strength than glulam can be used as a reinforcement on the glulam to give it higher strength. When the relative humidity is increased the glulam’s strength will decrease, the goal was to study how great the strength of the reinforced glulam beams would be when the relative humidity in the beams was being increased.In this essay a total of 26 glulam-samples was bent until they reached breaking point, out of these 26 samples half of them will be reinforced with carbon fiber underneath the beam. Half of the samples will be submerged in water, both reinforced and regular beams, where they will stay in two weeks until they are brought up again for bending-tests.The reinforced beams did not show an increase in torque capacity when compared to the non-reinforced beams when analyzing the average force. When analyzing the calculated 95 % -fractile the reinforced beams did show an increase in torque capacity. The dry reinforced glulam-beams showed an increase with 4,8 % and the wet reinforced glulam-beams showed an increase with 13,3 %.
6

Klijuotųjų medienių sijų jungties su įklijuotaisiai plieniniais strypais tyrimas / Investigation of connection of glulam beams with insetted steel bars

Gudelis, Andrius 02 July 2009 (has links)
Baigiamajame magistro darbe aptarti klijuotosios medienos su įklijuotaisiais plieniniais strypais privalumai bei trūkumai, jų panaudojimas ir taikymas statybos pramonėje. Atlikta plieno strypų, įklijuotų medienoje išilgai, skersai ir kampu į medienos pluoštus, teorinių skaičiavimų pagal Europos ir Rusijos normas metodikų analizė. Atlikti teoriniai standžios sijos jungties su įklijuotaisiais plieniniais strypais skaičiavimai. Išanalizuota bandymų metodika. Tiriamojoje dalyje atlikti šie eksperimentiniai bandymai: armatūros strypų takumo įtempių nustatymas; medienos tankio ir drėgnio nustatymas; strypų, įklijuotų medienoje išilgai, skersai ir 45o kampu į medienos pluoštus gniuždymo bandymai; sijos standžios jungties su įklijuotaisiais plieniniais strypais bandymas. Nustatyti esminiai rodikliai, veikiantys bandymų rezultatus, irimo pobūdžiai bei elgsena bandymų metu. Skaičiavimų rezultatai palyginti su eksperimentinių bandymų metu išbandytais natūralaus dydžio bandinių rezultatais. Darbe pateikti, įvertinti ir išanalizuoti teoriniai ir eksperimentiniai rezultatai, jų skirtumai. Pateiktos rekomendacijos ir pasiūlymai skaičiavimų metodikų tobulinimui ir praktiniam įklijuotųjų plieno strypų medienoje panaudojimui. / In this master degree paper are discussed advantages and imperfections, practice and use in construction industry of glulam with glued-in steel rods. Theoretical calculations analysis according to Eurocode and Russian standards of glued-in steel rods parallel, perpendicular and at an angle to the grain were made. Theoretical calculations of rigid joint glulam beam with glued-in steel bars were made. Tests methods were analyzed. In the part of the researches these tests were made: yield stress evaluation test of steel rods; moisture and density evaluation tests of wood; parallel, perpendicular ant at an 45 o angle to the grain compression tests of the glued-in steel rods; rigid joint of the glulam beam with glued-in steel rods test. Fundamental factors, which have influence to the results of the tests, character of the disruptions and the behavior of elements during the experiments were defined. The results of the calculations were compared with the results of tests in which natural size specimens were tried. In this work the results of theoretical calculations and experimental tests are proposed, evaluated and analyzed. The reasons of divergence in results are indicated. Recommendations and suggestions how to improve the methods of calculations and for better use the glued-in steel rods in the practice were offered.
7

Galerie letecké techniky a tradic letectví na letišti Medlánky v Brně / Gallery aviation technology and traditions of aviation at the airport Medlánky in Brno

Rebrova, Tatiana January 2016 (has links)
Area of the airport Medlánky is situated on the border of city districts Brno-Medlánky and Brno-Komín near the nature reserve "Medlánecké kopce". The designed gallery of aviation is a two-storey building, which consists of three parts. The main part is the exhibition space for airplanes, which is formed of a single-storey long-span hall, with the two-storey entrance part of the complex of buildings connected to it, in which are situated the area of the entrance, the training center (detached workplace of the institute of aviation FS BUT in Brno) and the administration. In the building of the original hangar, which is located along the street Turistická are located restaurants and aeroclub. Exhibition hall of the building of the gallery is formed by the structural system of the arched wooden glulam beams. The load-bearing wooden structures are visible and form the elements of the interior of the exhibition space. Two-storey extention of the entrance part of the building is structurally designed as a skeleton wooden structure. The material exception is the area of the entrance, which is made of monolithic concrete.
8

Sportovně relaxační centrum v Moravanech / Sports and Relaxation Center in Moravany

Pavel, Michal January 2017 (has links)
The subject of this thesis is the construction of Sport and relaxation center in Moravany. The building is divided into three objects. The first object is Bowling & Billiard Bar. The object is single-storey with no basement, flat roof and a total built area of 602,30 square meters. The second object is Technical and operational support + Fitness. The object has two floors, no basement, flat roof and a total built area of 757,40 square meters. The third object is Restaurant. The object is single-storey with no basement, flat roof and a total built area of 602,30 square meters. The building is designed in Porotherm constructional system. Ceiling structure is designed as a monolithic concrete slab. The roof system consists of wood glued laminated beams, purlins and rafters of solid wood. The slope of the roof plane is 3 %.

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