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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.
51

Effect of knots and holes on the fatigue strength of quarter-scale timber bridge stringers

Coffey, Daniel Joseph. January 1962 (has links)
Thesis (M.S.)--University of Wisconsin, 1962. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 29-31).
52

Flaring brush and ink Chinese calligraphy and painting centre /

Wong, Shan, Elaine. January 2002 (has links)
Thesis (M.Arch.)--University of Hong Kong, 2002. / Includes special study report entitled : Cultural background of Chinese calligraphy. Includes bibliographical references. Also available in print.
53

Stress analysis of wood stave pipe

McBean, Robert Parker January 1965 (has links)
At present the majority of wood-stave pipelines are supported on rigid cradles which bear on the lower 45% of the pipe circumference. The accepted method of analysis, developed by Regnell, completely ignores the stress concentrations induced in the staves just above the cradle tips. In this work, a full ring is proposed to distribute the support reaction to all staves and minimize deflections from a circular profile. From a consideration of equilibrium and stress-displacement relations for a stave element two fourth-order partial differential equations in terms of the radial and tangential displacements of the element are developed. Trigonometric series are applied to their solution. The support ring displacements are similarly described in series form. A study of the compatibility of ring and stave deflections removes the indeterminacy and all stress resultants, as functions of the ring or stave deflections, are then available from back-substitution. The formulas established are sufficiently complex that access to an electronic computer is a great practical advantage. In a numerical example, the effects of modifying the ring stiffness, hydraulic head, and the circumferential stiffness of the stave cylinder are investigated. The non-linear influence of ring and band tensions on the deformed shape of the structure is included. Design considerations are briefly discussed. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
54

Experimental studies on fracture of notched white spruce beams

Lau, Wilson Wai Shing January 1987 (has links)
The fracture problem due to the singular stresses arising from the sudden change of geometric properties around cracks and notches was studied both analytically and experimentally. The failure models of the cracked and the notched specimens were derived by using linear elastic fracture mechanics methodology, which led to the determination of the critical stress intensity factors. Experiments were conducted to determine fracture toughness for different modes as well as the effect of variations in the crack-front width, specimen size and moisture content. Subsequently, failure surfaces for cracks and notches were developed based on the experiments undertaken, describing in each case the interaction between mode I and mode II fracture toughness. To verify the reliability of these experiments, the results obtained were compared with the published literature. As an application, design curves for a 90 degrees-cracked beam and a 90 degrees-notched beam are presented. These curves allow the prediction of the failure loads due to the rapid crack propagation under different loading conditions. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
55

Grove Houses / Ny arkitektur i Flängan

Dahlberg, Mattias January 2015 (has links)
Is it possible to create new architecture in an area with a strict architectural costume without making a pastiche or turning your back against the existing architecture? The village of Flängan in Bergslagen is quintessential Swedish countryside. When moving along the gravelled main road, one can not help but notice the homogenous architectural character of the village - two story wooden houses with gable roofs, red-painted facades and white corners.  The project aims to create new architecture in such an area without being bound by the traditional formal rules of the existing houses, which is often copied to create new “contextual architecture”. / Är det möjligt att skapa ny arkitektur i ett område med en strikt arkitektonisk kostym utan att göra en pastisch eller vända ryggen mot den befintliga arkitekturen ? Byn Flängan i Bergslagen är emblematisk svensk landsbygd . När man rör sig längs grusvägen genom byn, kan man inte undgå att märka av områdets arkitektoniskt homogena karaktär - två våningars trähus med sadeltak, rödmålade fasader och vita knutar. Projektet syftar till att skapa ny arkitektur i ett sådant område utan att vara bunden av de traditionella formella reglerna i befintliga hus, som ofta kopieras för att skapa nya " kontextuell arkitektur " .
56

Investigation into the Landfilling and Recovery of Wood and Wooden Pallets at U.S. Landfills in 2021

Mansharamani, Yash 05 June 2024 (has links)
Pallets represent a large part of the North American solid wood market, with an estimated demand of 1.9 billion pallets in 2024, and 3.1 billion pallets in stock in 2019(Freedonia, 2020). In 2021, 1.18 billion pallets were produced, 919 million were new pallets, and 280 million were repaired or remanufactured (Hobbs, 2024). When pallets reach their end of life, they are landfilled, or recovered by grinding them for mulch or fuel. The objectives of this study are to quantify the number of pallets that are landfilled or recovered, investigate historical trends regarding wood waste at Municipal Solid Waste and Construction and Demolition landfills and investigate alternate uses for pallets. This study was conducted by sending out paper and electronic questionnaires to active landfills in the continental U.S. The study found that 76.8 million pallets, 8.4% of new pallets in 2021, end up in a landfill but 4% of these pallets will be recovered to some useful product such as mulch and only 4.4% will be buried in the landfill. Landfills encourage the population to separate wood before they send material for landfilling, and they are doing this with lower tipping fees. Landfills indicated alternate uses for recovered pallets include alternate daily cover, to ship e-waste, used for road base, given to residents and chipped for mulch or fuel. The study found that 95-97% of wooden pallets produced in the U.S. are repaired for reused, used for repairing other pallets, or converted into value adding by-products. / Master of Science / Pallets are an important part of the supply chain, with 95% of all US packaged products being shipped on pallets. 95% of the demand of pallets are for wooden pallets (Freedonia). This study focuses on investigating the landfilling and recovery of wooden pallets at MSW (general waste) landfills and CandD (construction and demolition waste) landfills. The study was conducted using a survey which was send to both types of landfills. It was found that over 95% of wooden pallets are recovered in some shape or form.
57

Fundamental frequencies of I-joist, solid-sawn wood joist, and truss floors based on tee-beam modeling

Runte, David E. 19 September 2009 (has links)
Full size wood joist floors were built and their frequencies were measured. Double tee-beam floors were built and also cut from the full size floors and their frequencies were measured. The floor joists investigated included: solid sawn, parallel chord floor trusses, and composite I -joists. The first natural frequency of each tee-beam floor was predicted after measuring the deflection under imposed loading. A design procedure is presented to predict the fundamental frequency of wood joist floors from tabulated material properties / Master of Science
58

The effect of stiffness and mass on the dynamic response of wood floors

Li, Xiaoming 11 June 2009 (has links)
This thesis describes the effects of coefficient of variation (COV) of joist modulus of elasticity (MOE), floor mass and stiffness, imposed load, and boundary conditions on the floor vibrational performance. Three main parameters used to describe the vibration are resonant frequency, damping ratio, and root mean square (RMS) acceleration. The results showed that COV of joist MOE affected the fundamental frequency, and had no significant effect on damping ratio and RMS acceleration. The floor mass and stiffness affected all the three parameters to different degrees. Imposed load affected most of the vibrational parameters. The boundary conditions investigated affect the mode 2 resonant frequency, but have no significant effect on the damping ratio and RMS acceleration. In addition, the load sharing capacity was evaluated in terms of the percentage of load carried by each joist within a floor. / Master of Science
59

Analysis and computer program for non-prismatic continuous beam and floor section

Maghsood, Javad January 1967 (has links)
M.S.
60

A hierarchical analysis of factors affecting the adoption and marketing of timber bridges

Smith, Robert L. 04 April 2009 (has links)
Several aspects influencing the adoption of timber bridges were investigated. Initially, perceptions of timber as a bridge material were rated by highway officials in twenty-eight states. Timber was rated lowest in overall performance by each group (State Department of Transportation engineers, private consultants, and local highway officials) throughout the United States. The highest rated bridge material was prestressed concrete, followed by reinforced concrete, steel and timber. The most important factors in the bridge material decision included: Lifespan of material, past performance of material, maintenance requirements of material, resistance to natural deterioration, initial cost, and lifecycle cost. Timber was compared to other bridge materials on eight preselected attributes. Timber rated the lowest on the attributes of low maintenance, ease of design, long life, and high strength. Highway officials in four states (Mississippi, Virginia, Washington, and Wisconsin) were personally interviewed. The Analytic Hierarchy Process (AHP) was used to characterize their decision of a bridge material. The most important bridge criteria were similar in each state, however, their effect on the overall decision differed by state. Prestressed and reinforced concrete were the materials of choice in all states. The results of this study indicate that, based on the six criteria measured, timber will seldom be the material of choice for highway bridges. Timber bridge manufacturers were surveyed to understand current marketing and management techniques in the promotion of timber bridges. Marketing efforts were most prevalent in the Midwest. Timber bridge sales represented, on average, less than 7% of total sales from responding companies. Wood treating and gluelaminating firms represented over 75% of the timber bridge firms. One-half of the responding timber bridge companies felt that timber bridge sales would increase an average of 15% over the next five years. Barriers and incentives to timber bridge adoption were investigated. The greatest incentives include: year around construction, resistance to deicing chemicals, quick construction, and aesthetic qualities. Major barriers appear to be: short lifespan, maintenance requirements, decay, perceptions of strength, and that "timber doesn't perform well under high weight and traffic volumes". The realistic size of the bridge market was estimated not to exceed 600 to 700 designed bridges a year. This would require the use of 10 to 12 million board feet of lumber. / Ph. D.

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