Sökresultat:
3066 Uppsatser om Mechanics for resilient construction element - Sida 8 av 205
Analysmetoder för rörsystem
The purpose of this thesis work is to evaluate how the physical behaviour of a pipe bend is affected by the pipe bending procedure. Effects such as initial ovalization, thinning, thickening and plastic hardening from the bending procedure are examined and the mechanical properties of pipe bends containing these effects are investigated.This has been evaluated by creating a detailed Finite Element model of a pipe that is being bent. Then the differences compared to a bent tube in a virgin state, so called Elbow elements and an analytical in-house program have been evaluated. The virgin state refers to a model of a pipe that is bent from the beginning, thus having a homogeneous thickness and not containing any plastic hardening. The Elbow element is a calculationally cheap element, specially developed for accurate calculations of pipe bends in an initially virgin state.The goal with the thesis work is to get a better picture of what happens to a pipe as it is being bent, how this affects the mechanical properties and to evaluate the possibility to develop an easy method for taking these effects into account when using the Elbow element.This report describes the layout of the work and how the detailed FE-model has been constructed.
Lufttäta byggnader
The viscosity of air buildings is a hot topic within the construction performers, which the industry feel they have too little knowledge about. This study is mainly aimed against air density in apartment buildings and airflow measurement. The study consists of a theoretical reference, educational visit, interviews and a survey conducted among construction workers at Magistratshagen in Linkoping.Earlier requirement in terms of air leakage through the climate screen was removed and today there are only energy requirement for a dwelling in Boverkets Building Regulations. The difference between a passive and a typical air tight construction is that the passive house have a maximum requirement of 0.3 l /s m2 of air leakage through the building climate screen. The requirement imposed on passive houses is to minimize the supply of power and energy for heating the building.Air tight constructions have heavy demands on the performance and accuracy of everyone involved with the project. The client must specify their requirements and also be prepared to pay for any additional costs. The architect and building planners have to design the building with regard to air tightness. Finally, the construction workers are required to do a careful work in order to get all the connections in the building air tight.The study suggests that an air tight building is a closed system where no forced ventilation exists. There are no reasons not to build too tight as long as there is a functioning ventilation. In this study the authors ask themselves how an air tight building changes over time. No theoretical information has been found on these changes, but the respondents assume that air density decreases with time. The deterioration is mainly assumed to be caused by construction materials changes over time. The study shows that construction workers knowledge of air tight construction is mixed, which they themselves admit in the survey..
Prefabricerade passivhusväggar
Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments.
Jämförelsestudier av Takkonstruktioner med Stora Spännvidder
The purpose of this report is to examine various roof structures that can operate in a warehouse with large spans. The building that is examined in the report is currently under construction, and the roof construction has already been selected. The selected roof system will therefore be compared with some other structures and materials that have been possible. The report will evaluate three different frame materials, two insulating barriers and two overlaying materials. Another important part in major construction projects is the roof safety.
Effektivisering av logistiklösningar : En jämförelse av nya och gamla logistiksystem vid ROT-projekt
A persistent problem in the construction industry is its low margins of profit. It is often difficult to earn money due to low efficiency and high costs. Logistics on the construction site answers for a large amount of these costs and it is therefore of interest to find new, more efficient logistic solutions. The purpose of this thesis is to compare two different logistic systems and further to evaluate which one that is the most efficient and profitable. A comparison is made between the traditional logistic systems used for years and a new logistic system developed by an industry association called BEAst.
Lean Construction inom en geografiskt begränsad marknad
Syftet med studien är att undersöka om en geografiskt begränsad marknad inom byggbranschen underlättar en implementering av Lean Construction. För att undersöka detta har jag utgått från två forskningsfrågor: vilken inställning de tillfrågade byggföretagen har till Lean Construction och hur de arbetar utifrån ett Lean-perspektiv? Utifrån ett antal grundprinciper från Lean Construction formades en enkät för datainsamling. Resultaten från undersökningen visade att respondenterna som bestod av platschefer/arbetsledare och underentreprenörer överlag tyckte att de områden som tagits upp var viktiga för en lyckad byggprocess och en stor del av respondenterna även arbetade utifrån ett Lean-perspektiv. Enkätundersökningen tog upp nio områden: samarbete, Visible Planning med detaljerade veckoplaner, Just-In-Time, slöseri, standardisering, Kaizen, innovationer, Last Planner med arbetsplanering och Percent Plan Complete från Last Planner konceptet.
Alternativ motorinkapsling
The problems caused by the current engine casing in aluminum for Volvo Buses Corp. are the mainfoundation for this degree project. Lack of maintenance combined with a construction poorlyadjusted for assembly has resulted in the fact that the engine casings rarely get reassembled whenthe service is completed.The degree project has mainly been following ?Olssons. F, Principkonstruktion, Compendium, Lund?and ?Olssons.
Hållbart ansvarstagande för ett medelstort byggföretag i Sverige - En analys av värdeskapande aktiviteter som bidrar till hållbar utveckling.
This report deals with activities that from a CSR perspective are considered to create a shared value for a medium-sized construction company in Sweden. The CSR definition used in the report is the European Commission?s since it reflects the valuecreating aspects of CSR, in contrast to the traditional philanthropic aspect of CSR.Companies in the building construction industry have difficulties identifying activities that create value in society and in the company. The aim with the project is to, from a CSR perspective, identify and evaluate value creating activities in a building construction company. The activities will be evaluated with respect to competitiveness and how they can be implemented into an organization.
3-D handlingar, GPS-styrning och VA-moduler- En ny metod för framtida anläggningsprojekt
Ground construction has to a large extent been dominated by traditional meth-ods during the last 50 years. Although the construction has been changed meanwhile innovations are not accepted. In collaboration with NCC Ltd Region South, I have examined a modern con-struction methodology that has been developed by NCC for future large pro-jects. The method is divided into two central phases. Phase 1 is? Single Pro-duction? which is a preliminary period for ground constructions to come.
Upprättande av mall för fuktsäkerhetsbeskrivning : Genom granskning av projekt ur fuktsäkerhetssynpunkt
During the 1990?s a large number of building projects were revealed where lack of moistsafety precautions during the construction process had led to extensive moisture damage. Alsoresent implemented studies have shown that the problems with moisture damages have ratherincreased than decreased during the past few years. Moist is considered to be one of the mainfactors to cause unhealth due to deficiencies in the indoor-environment and does also causeunnecessary expenses and a reduction of the confidence in the construction industry.In this Bachelor of Science thesis three projects have been reviewed to examine how moistsafetyhas been observed during the construction process. Main focus has been to identify thebuilding components that are the most exposed to moist, and to examine how they have beentaken into account during the period of design and construction.
Kategorisering av idésyften : En kvalitativ analys av idéer i Volvo Construction Equipment?s idéhanteringssystem
Syftet med detta examensarbete är att på uppdrag av Volvo Construction Equipment hitta en metod för att hantera och kategorisera idéflödet i deras idéhanteringssystem Interact. Den metod som användes var kvalitativ innehållsanalys. Slutsatsen är att metoden gick att använda för att kategorisera idéflödet men att ett material som sträcker sig över många ämnen tenderar att sänka tillförlitligheten på resultatet. Vidare bedöms materialet som detta arbete har producerat kunna användas för att bättre ta tillvara på idéer, vilket uppskattas av Volvo Construction Equipment..
Nollavräkning av entreprenadprojekt: Teoretisk grund och praktisk betydelse
The purpose of this study is to investigate the method called zero recognition that is used in accounting for construction contracts when the outcome is uncertain. When this is the case it is hard to make the necessary estimates needed for the percentage of completion method to be used. Both the meaning of the method from an accounting perspective and the practical importance and purpose of the method is investigated. The method used for this study is the qualitative one and the deductive model is used to relate the theory with the empirical research. The theoretical background consists of accounting theory and theories about individuals, companies and markets.
Risk eller Resurs: En studie av hur riskbegreppet konstrueras i den svenska kärnkraftsdebatten
Looking at the debate on nuclear power in Sweden, the issue of risk is central to understanding the difficulties in resolving differences between proponents and opponents. I sought to answer the research question: "how is the concept of risk constructed in the nuclear power debate in Sweden?" Four main aspects of risk construction were defined and investigated to identify differences between sides in the debate. Through a qualitative study of the debate and its actors I found clear differences in respect to all four aspects of risk construction. First, the perception of nuclear power as a "normal risk" is common among nuclear opponents in contrast to a largely probabilistic view among proponents.
Skyddsombudets Roll : En undersökning av skyddsombudets säkerhetsarbete på byggarbetsplatsen
Safety in the construction industry has become a question of top priority in recent years. Despite a massive investment of time, money and knowledge, the occur-rence of fatal accidents in Sweden alone is around one a month.The purpose of this study is therefore to improve the safety on the construction site. By an examination of the role of the safety agents and their cooperation with the construction workers and supervisors as well as examine how safety agents can improve safety on the construction site, which is the goal of the study.Four questions were formulated based on the purpose and the goal of the study.The methods used to answer the questions were a questionnaire survey, multiple interviews, a literature review and a document analysis.The report describes the safety agent?s role as a complex one with many different tasks. The role of the safety agents is regulated in the health and safety law, but it can sometimes be difficult to interpret and the agents can therefore interpret their role differently.
Säkrare arbetsmiljö på byggarbetsplatser : Hur brister på arbetsplatser borde åtgärdas för att kunna arbeta på en mer hälsosam arbetsmiljö
Work Environment problems on construction work sites are very extensive and discussed. The construction industry is one of the most dangerous industries in Sweden. The construction industry occupies about 290 000 employment (2009), and the investment was 250 billion SEK. This report will investigate the issues of the work environment and offer advice on how these can be measured and imporved. The study includes review and analyses of occupational injury statistics, interviews, inspections and audit and review of the literature.