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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

Stiffness Factors in Material Efficiency for Automotive Application

Ng, Wei Loong 04 August 2001 (has links)
The automotive industry is moving towards a new generation of lightweight vehicles for improved fuel economy and reduced pollution. However, the industry wants to keep the vehicle size without sacrificing performance, affordability, and safety. Hence, every component which makes up an automobile, from body structure to engine and interior, are scrutinized in pursue of weight savings. Efficient geometrical design and careful material utilization are ways to bring about a significant weight reduction in the auto body. This research will show techniques to predict areas in auto body that potentially have weight savings possibility. A formula is developed to determine the relevancy of substituting steel, the material used primarily in auto body, with aluminum for the equivalent structural stiffness from weight savings standpoint. Also, the same formula can provide geometrical guideline for an efficient body structure. Finite Element Modeling software ALGOR is employed in this research to determine the maximum deflection of an auto floor pan, before and after geometrical and material alteration.
2

Material efficiency in construction

Moynihan, Muiris January 2014 (has links)
Producing steel causes 6% of global anthropogenic carbon dioxide emissions. Experts recommend that these emissions are reduced by half by the year 2050 in order to avert the worst consequences of climate change. Demand for steel is predicted to double in the next 36 years, meaning that a 75% reduction in emissions per unit of steel produced is necessary to reach the recommended limit. Process efficiency improvements cannot deliver this magnitude of reduction; however if steel is used more efficiently so that less new material is required to deliver the same service - a concept termed 'material efficiency' - then this could allow demand to be satisfied whilst emissions targets are achieved. Construction is the single largest use of steel globally, therefore using steel more efficiently in construction will reduce emissions. Three material efficiency strategies are identified as having most potential for this industry: using less material, using products for longer, and reusing components. In order to prioritise areas for research, steel flows into construction are mapped, finding that industrial buildings and utility infrastructure are the largest users of steel, while superstructure is confirmed as the main use of steel in a typical building. To estimate the potential to use less steel in buildings, 23 steel-frame designs are studied, sourced from three leading design consultancies. The utilisation of each element is found and the building datasets are analysed to infer the amount of steel over-provided. The results suggest that such buildings contain almost twice as much steel as necessary for structural performance, and indicate that this amount of over-provision occurs to minimise labour costs, which are a larger proportion of total costs than materials. To investigate how buildings and infrastructure could be used for longer, reasons for their failure are reviewed. Based on interviews with industry professionals a set of strategies is proposed, tailored to each failure cause and distinguishing between cases where failure can and cannot be reasonably foreseen. Steel sections could be reclaimed from old buildings and reused in new buildings but this does not occur because they are damaged during demolition. Designing for deconstruction would facilitate reuse but is not practised due to its cost. Data from interviews and a commercial working group are analysed to identify three aspects of designing for deconstruction that provide financial and operational benefits to clients, thus encouraging their use. One remaining technical barrier to deconstruction is composite steel-concrete systems, where welded connectors make it impractical to separate the steel beam from the concrete slab without damage. A novel bolted composite connector is proposed and tested in three beam experiments. The bolted connector allows successful separation of the components, facilitating reuse. Its structural performance is similar to that of welded connectors and can be predicted using current design standards. Each of the investigations reveals significant opportunities to reduce steel use in construction by using material more efficiently. Achieving these savings would reduce demand for new steel production and thereby decrease carbon dioxide emissions.
3

Increasing the Structural Engineer’s Influence Over Sustainability By Using Integrated Design Teams

French, Mary Elizabeth 01 August 2010 (has links)
Sustainability is quickly becoming a “buzz word” in today’s environmentally conscious world from political leaders to building professionals to design experts to consumers as they rethink their impact on current healthy, efficient indoor/outdoor environments as well as long term benefits to future generations. This paper seeks to investigate ways to increase the structural engineer’s influence over the sustainability of the building industry by using integrated design teams. It explores current practices within the building industry, in particular the housing industry and the ways in which the integrated design team differs from most current practices. It strives to promote the positive impact an integrated design team with structural engineers on board from the onset has on the design process as far as time, cost, and environmental concerns are considered. This paper continues by establishing methods for measuring the success of an integrated design team,its effects on sustainability, and how the structural engineer was involved. The focus of this paper is the New Norris House class project: its background and the integrated design team’s process as it differs from the traditional design concept. The results of the project including the LEED and HERS rating and material efficiency and the impact of the structural engineer’s inputs from the onset will be discussed. The paper ends with a discussion on the differences between the educational and professional community and how integrated design teams are an efficient and cost effective way to achieve high levels of sustainability.
4

Increasing the Structural Engineer’s Influence Over Sustainability By Using Integrated Design Teams

French, Mary Elizabeth 01 August 2010 (has links)
Sustainability is quickly becoming a “buzz word” in today’s environmentally conscious world from political leaders to building professionals to design experts to consumers as they rethink their impact on current healthy, efficient indoor/outdoor environments as well as long term benefits to future generations.This paper seeks to investigate ways to increase the structural engineer’s influence over the sustainability of the building industry by using integrated design teams. It explores current practices within the building industry, in particular the housing industry and the ways in which the integrated design team differs from most current practices. It strives to promote the positive impact an integrated design team with structural engineers on board from the onset has on the design process as far as time, cost, and environmental concerns are considered. This paper continues by establishing methods for measuring the success of an integrated design team,its effects on sustainability, and how the structural engineer was involved.The focus of this paper is the New Norris House class project: its background and the integrated design team’s process as it differs from the traditional design concept. The results of the project including the LEED and HERS rating and material efficiency and the impact of the structural engineer’s inputs from the onset will be discussed. The paper ends with a discussion on the differences between the educational and professional community and how integrated design teams are an efficient and cost effective way to achieve high levels of sustainability.
5

Paper re-use : toner-print removal by laser ablation

Leal Ayala, David Ricardo January 2012 (has links)
No description available.
6

Evaluating material efficiency assessment methods : An assessment of the adaptability to B2B products using Ericsson telecom network infrastructure product as a case study

Hederén, Amanda January 2018 (has links)
Unsustainable consumption patterns and material scarcity has been recognised as one of the challenges within the European Union. To change these patterns policy makers within EU are looking towards a transitioning into circular economy. Electronics and manufacturers of energy related products is found to be important actors in this transition, due to the unsustainable trends of consumption and the materials of important contained in electronics. Energy related products are regulated by the Eco design directive (Directive 2009/125/EC) containing implementing measures on energy efficacy. Today the directive is lacking methods for assessing material efficacy in energy related products. CEN/CENELEC was 2015 requested to develop standard methods on how to assess the material efficiency aspects; durability, ability to reuse, repair, upgrade, re-manufacturabiliy, recyclability and recoverability and use of recycled content and CRM content. This study sets out to assess the adaptability of the preliminary publications of the standards on to an Ericsson radio network product. The study is divided into two parts, part one assesses the general and product specific implementation of the selected standard documents. The first parts of this study are document analysis and seven interviews used to triangulate the general opinions on the standards. In part two the study sets out to test two of the methods found in the standard documents. The study found in the collection of recycling data and rates for a small radio network product, the product had a recyclability of XX% and a recoverability of XX% and a time for disassembly of XX seconds using the suggested method eDiM. The findings of this study suggest that these standardised methods are welcomed by the telecommunications equipment manufacturer but concerns on the amount of data required, future purpose and the reliability of the assessment methods still creates worries for the future. / Ohållbara konsumtionsmönster och materialbrist har erkänts som en av de största utmaningarna inom europeiska unionen. För att förändra dessa mönster så har beslutsfattare inom EU påbörjat omställningen till den cirkulära ekonomin. Elektronik och tillverkare av energirelaterade produkter har erkänts som viktiga aktörer i denna omställning, på grund av den ohållbara konsumtionsutvecklingen under det senaste decenniet och de viktiga material som används för att tillverka elektronikprodukter. Energirelaterade produkter regleras av Eco design direktivet (direktiv 2009/125 / EG) som idag innehåller implementeringsåtgärder för energieffektivitet i energirelaterade produkter. I framtiden kommer det även finnas implementeringsåtgärder för materialeffektivisering men idag saknas standardiserade metoder för bedömning av material effektivitet. År 2015 tillförordnades CEN/CENELEC uppdraget att ta fram och utveckla standarder för bedömning av materialeffektivitetsaspekterna; livslängd, återanvändning, reparerbarhet, uppgraderingsbarhet, återtillverkning, återvinningsbarhet och användningen av återvunnet material och innehåll av kritiska råmaterial. Den här studien syftar till att analysera användbarheten hos de preliminära publikationerna av standarderna inom ramen för Ericssons verksamhet. Studien är uppdelad i två delar, del ett bedömer det allmänna och produktspecifika genomförbarheten av de utvalda standarddokumenten. Resultatet från del ett baseras på en dokumentanalys och sju intervjuer, som används för att triangulera de generella åsikterna om standarderna. I del två testas två av metoderna ur standarddokumenten. Resultatets av testerna visar att den utvalda nätverksprodukten hade en återvinningsbarhet på XX% och en återhämtning på XX%. Studien visar även att nätverksprodukten hade en tid för demontering på XX sekunder när den föreslagna metoden eDiM användes. Resultaten av denna studie tyder på att dessa standardiserade metoder välkomnas av Ericsson men mängden data, framtida syfte och pålitligheten av bedömningsmetoderna skapar oro för framtiden.
7

Site-level resource efficiency analysis

Gonzalez Hernandez, Ana January 2018 (has links)
To achieve agreed targets for reducing global carbon emissions, industry must become more resource-efficient. To this end, two viable strategies exist: energy efficiency and material efficiency. Despite their inherent interdependence, industry continues to treat these two strategies as isolated pursuits, providing in the process only a partial insight into the potential of resource efficiency. To resolve this disconnect, this thesis attempts to develop and apply tools that help integrate industrial energy and material efficiency analyses. Three areas of research are explored. The first is concerned with a fundamental component of industrial performance: efficiency benchmarks. No agreed-upon metric exists to measure the efficiency with which the sector trans- forms both energy and materials - that is, how resource-efficient they are. This thesis applies exergy - a well-established method to consolidate energy and materials into a single metric - to a case study of the global steel industry in 2010. Results show that this exergy-based metric provides a suitable proxy to capture the interactions between energy and materials. By comparing energy and material efficiency options on an equal footing, this metric encourages the recovery of material by-products - an intervention excluded from traditional energy efficiency metrics. To realise resource efficiency opportunities, individual industry firms must be able to identify them at actionable time-frames and scopes. Doing this hinges on understanding resources flows through entire systems, the most detailed knowledge of which resides in control data. No academic study was found to exploit control data to construct an integrated picture of resources that is representative of real operations. In the second research area, control data is extracted to track the resource flows and efficiency of a basic oxygen steel-making plant from TataSteel. This second case study highlights the plant's material efficiency options during operations. It does so by building close-to-real-time Sankey diagrams of resource flows (measured in units of exergy) for the entire plant and its constituent processes. Without the support of effective policies the new exergy approach is unlikely to be widely adopted in industry. By collating evidence from interviews and policy documents, the third area explores why the European Union's industrial energy and emissions policies do not incentivise material efficiency. Results suggest several contributing factors, including: the inadequacy of monitored indicators; an imposed policy lock-in; and the lack of a designated industry lobby and high-level political buy-in. Policy interventions are then proposed to help integrate material efficiency into energy and climate agendas. The European Union's limited agency stresses the need for Member States and industry to drive the move to a low-carbon industry in the short-term.
8

MATERIAL EFFICIENCY MANAGEMENT IN MANUFACTURING

Shahbazi, Sasha January 2015 (has links)
Material efficiency is a key solution to provide a reduction in the total environmental impact of global manufacturing, which contributes to avoid generating larger volumes of industrial waste, to reduce extracting and consuming ever more resources and to decrease energy demand and carbon emissions. However, the area of material efficiency in manufacturing has been under-researched and related knowledge is limited. The research objective of this thesis is to contribute to the existing body of knowledge regarding material efficiency in manufacturing - to increase understanding, describe the existing situation and develop support for improvement. This thesis focuses on value of process and residual materials in material efficiency: to increase homogenous quality of generated waste with higher segregation rate, decreasing the amount of material becoming waste and reduce total virgin raw material consumption without influencing the function and quality of a product or process. To achieve the objective, material efficiency strategies, existing state of material efficiency in manufacturing and barriers that avert higher material efficiency improvement have been investigated. The results are supported by four structured literature reviews and two [MW1] empirical multiple case studies at large global manufacturing companies in Sweden, mainly automotive. Empirical studies include observations, interviews, waste stream mapping, waste sorting analysis, environmental report reviews and walkthroughs in companies to determine the material efficiency and industrial waste management systems. The empirical results revealed that material efficiency improvement potential of further waste segregation to gain economic and environmental benefits is still high. Determining different waste segments and relative fractions along with calculating material efficiency performance measurements facilitate improvements in material efficiency. In addition to attempts for waste generation reduction, avoiding blending and correct segregation of different waste fractions is an essential step towards material efficiency. The next step is to improve the value of waste fractions i.e. having more specific cost-effective fractions. Waste Flow Mapping proves to be an effective practical tool to be utilized at manufacturing companies in order to check and explore the improvement opportunities. In addition, a number of barriers that hinder material efficiency was identified. The most influential material efficiency barriers are Budgetary, Information, Management and Employees. The majority of identified material efficiency barriers are internal, originate inside the company itself and are dependent upon the manufacturing companies’ characteristics. As a result, management and employees’ attitude, environmental knowledge and environmental motivation, as well as their internal communication and information sharing, and companies’ core value and vision are the enablers for material efficiency improvement. / MEMIMAN / INNOFACTURE - innovative manufacturing development
9

Stochastic Lattice | A Generative Design Tool for Material Conscious Free Form Timber Surface Architecture

Schmid, Matthew 30 April 2012 (has links)
This thesis attempts to resolve the contradictory relationship between the ecological merits of wood construction and the significant material intensity of recent free form timber surface structures. The building industry is now adept in the design and construction of freeform surface architecture, however new challenges have been introduced with the environmentally conscious desire to build these structures in wood. Lacking the formal versatility of steel and concrete, wood introduces a great deal of difficulty in the realization of complex form at an architectural scale. Powerful digital design and fabrication tools have recently made it possible to model, analyze and construct these buildings, but at the cost of heavy structural solutions that involve energy intensive fabrication processes and significant material waste. This approach contradicts the ecological benefits of wood, and raises the question of whether it is possible to achieve free and expressive form in timber surface architecture while maintaining an economy of means and material. This question is addressed through the development of a generative design tool for the creation of material conscious free form timber surface architecture. The formation of the tool is informed by the field of computational morphogenesis, which draws from the natural growth processes of biological structures in the virtual synthesis of form. The tool is conceived as a morphogenetic material system, which consists of a generative algorithm that integrates material, structure and form in a single computational process. Specific material saving techniques deployed in the algorithm draw from existing research in timber shell design and material optimization. Established methods in the use of geodesic lines for the structural patterning of wood shells and stress driven material distribution make up the core concepts deployed in the algorithm. The material system is developed, refined and tested through the design and construction of an experimental free form timber lattice.
10

Stochastic Lattice | A Generative Design Tool for Material Conscious Free Form Timber Surface Architecture

Schmid, Matthew 30 April 2012 (has links)
This thesis attempts to resolve the contradictory relationship between the ecological merits of wood construction and the significant material intensity of recent free form timber surface structures. The building industry is now adept in the design and construction of freeform surface architecture, however new challenges have been introduced with the environmentally conscious desire to build these structures in wood. Lacking the formal versatility of steel and concrete, wood introduces a great deal of difficulty in the realization of complex form at an architectural scale. Powerful digital design and fabrication tools have recently made it possible to model, analyze and construct these buildings, but at the cost of heavy structural solutions that involve energy intensive fabrication processes and significant material waste. This approach contradicts the ecological benefits of wood, and raises the question of whether it is possible to achieve free and expressive form in timber surface architecture while maintaining an economy of means and material. This question is addressed through the development of a generative design tool for the creation of material conscious free form timber surface architecture. The formation of the tool is informed by the field of computational morphogenesis, which draws from the natural growth processes of biological structures in the virtual synthesis of form. The tool is conceived as a morphogenetic material system, which consists of a generative algorithm that integrates material, structure and form in a single computational process. Specific material saving techniques deployed in the algorithm draw from existing research in timber shell design and material optimization. Established methods in the use of geodesic lines for the structural patterning of wood shells and stress driven material distribution make up the core concepts deployed in the algorithm. The material system is developed, refined and tested through the design and construction of an experimental free form timber lattice.

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