• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 3
  • 1
  • Tagged with
  • 26
  • 26
  • 11
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 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.
11

Experiences with Prefabrication and Habitat for Humanity

Bilson, Carolyn Mary January 2007 (has links)
This thesis chronicles my experiences with developing a panelized wall system for use by Habitat for Humanity and with testing that system in the design and construction of a house. Presented as a series of narratives, it follows the progress of the project from August 2003 to December 2005. Described is my motivation to test my theories through design and construction, the applicability of prefabrication to Habitat for Humanity’s use of unskilled volunteer labour, the incorporation of panelization into the design of a house for the Waterloo Region affiliate of Habitat for Humanity, the prefabrication of preclad wood framed wall panels for this house by students at the University of Waterloo School of Architecture, the erection of these wall panels on-site, and the completion of the house to a weathertight state. The thesis concludes with discussions of the understanding I gained through my experiences, the necessity for further development and testing of the panelized wall system, and the future use of prefabrication by Habitat for Humanity.
12

Development of wood flour-recycled polymer composite panels as building materials : a thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in Chemical and Process Engineering in the University of Canterbury /

Adhikary, Kamal Babu. January 2008 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.
13

Behavior of reinforced concrete panels constructed of high strength materials

Robert, Stephen Douglas 01 May 2010 (has links)
Concrete structures designed to meet blast criteria often require substantial increases in structural system size, weight, and cost when using conventional materials, but using higher strength materials may offer a way to mitigate these increases while achieving desired performance levels. The primary objective of this research is to investigate the performance of a high-strength Portland cement concrete, high-strength low-alloy vanadium (HSLA-V) rebar material combination that meets or exceeds blast resistance criteria while allowing a more efficient structural design than can be achieved using conventional materials. Twelve panels consisting of both single and double mat conventional Grade 60 rebar or HSLA-V rebar in combination with 4 ksi or 15 ksi concrete were tested using the ERDC quasi-static water chamber. Permission to publish this thesis was granted by the Director of the Geotechnical and Structures Laboratory and the U.S. Army Research Laboratory.
14

Beyond the Institution: The Making of a Visual and Conceptual Playground

mcleran, jennifer 21 March 2000 (has links)
this thesis Presents an exploration of the residence hall as an institution through formal and conceptual play. / Master of Architecture
15

Examining the effects of openings at the base of slender reinforced concrete (tilt-up) wall panels subjected to varying wind pressures

Cook, Andrew January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Kimberly Waggle Kramer / This report examines the effects of openings located at the base of reinforced concrete slender wall panels (tilt-up panels) designed in accordance with the American Concrete Institute (ACI) Committee 318-11 Building Code Requirements for Structural Concrete Section 14.8 Alternative Design of Slender Walls. The parametric study calculates the reinforcement (longitudinal) required for specific panels in accordance with ACI 318-11 Section 14.8 and compares the designs to a finite element analysis conducted with SAP 2000 version 14 to determine the appropriateness of the assumptions made in Section 14.8. Furthermore, this report compares the design of a tilt-up panel designed by Section 14.8 Alternative Design of Slender Walls and designed by Section 10.10 Slenderness Effects in Compression Members.
16

Experimental and Theoretical Studies of Normal and High Strength Concrete Wall Panels

Doh, Jeung-Hwan, n/a January 2003 (has links)
The wall design equations available in major codes of practice (e.g. AS3600 and ACI318) are intended for the design of normal strength concrete load bearing walls supported at top and bottom only. These codes fail to recognise any contribution to load capacity from restraints on the side edges. They also fail to give guidance on the applicability of the equations to high strength concrete. Further, they do not consider slender walls. In many situations walls have side edges restrained and are composed of high strength concrete with high slenderness ratios. The recognition of these factors in the codes would result in thinner walls and consequently savings in construction costs. In this thesis, the focus is on the development of a design formula and new design methods for axially loaded reinforced concrete wall panels. The design of walls having side restraints and being composed of high strength concrete is given particular attention. An experimental program has been undertaken to obtain data for the derivation of applicable formulae and to verify the analytical methods developed herein. Note that, the test results and other data available in published literature have also been used to develop the design formula. The formula encompasses effective length, eccentricity and slenderness ratio factors and is proposed for normal and high strength concrete walls simply supported at top and bottom only (one-way) and simply supported on all four sides (two-way). The major portion of the experimental program focuses on a series of normal and high strength concrete walls simply supported at top and bottom only (one-way), and simply supported on all four sides (two-way) with eccentric axial loading. The behaviour of the test panels is noted, particularly the difference between the normal and high strength concrete panels. A Layer Finite Element Method (LFEM) is used as an analytical tool for walls in two-way action. The LFEM gives comparable results to the test data and the proposed design formula. As part of the research, a program named WASTABT has also been developed to implement a more accurate analytical method involving the instability analysis of two-way action walls. WASTABT is proven to be a useful design tool in situations where the walls have (i) various reinforcement ratio in one or two layers; (ii) composed of normal or high strength concrete; (iii) various eccentricity.
17

Seismic Performance Assessment of Multi-Storey Buildings with Cold Formed Steel Shear Wall Systems

Martinez Martinez, Joel January 2007 (has links)
Cold-Formed Steel (CFS) is a material used in the fabrication of structural and non-structural elements for the construction of commercial and residential buildings. CFS exhibits several advantages over other construction materials such as wood, concrete and hot-rolled steel (structural steel). The outstanding advantages of CFS are its lower overall cost and non-combustibility. The steel industry has promoted CFS in recent decades, causing a notable increase in the usage of CFS in building construction. Yet, structural steel elements are still more highly preferred, due to the complex analysis and design procedures associated with CFS members. In addition, the seismic performance of CFS buildings and their elements is not well known. The primary objective of this study is to develop a method for the seismic assessment of the lateral-load resistant shear wall panel elements of CFS buildings. The Performance-Based Design (PBD) philosophy is adopted as the basis for conducting the seismic assessment of low- and mid-rise CFS buildings, having from one to seven storeys. Seismic standards have been developed to guide the design of buildings such that they do not collapse when subjected to specified design earthquakes. PBD provides the designer with options to choose the performance objectives to be satisfied by a building to achieve a satisfactory design. A performance objective involves the combination of an earthquake (i.e., seismic hazard) and a performance level (i.e., limit state) expected for the structure. The building capacity related to each performance level is compared with the demand imposed by the earthquake. If the earthquake demand is less than the building capacity, the structure is appropriately designed. The seismic performance of a CFS building is obtained using pushover analysis, a nonlinear method of seismic analysis. This study proposes a Simplified Finite Element Analysis (SFEA) method to carry out the nonlinear structural analysis. In this study, lateral drifts associated with four performance levels are employed as acceptance criteria for the PBD assessment of CFS buildings. The lateral drifts are determined from experimental data. In CFS buildings, one of the primary load-resistant elements is Shear Wall Panel (SWP). The SWP is constructed with vertically spaced and aligned C-shape CFS studs. The ends of the studs are screwed to the top and bottom tracks, and structural sheathing is installed on one or both sides of the wall. For the analysis of CFS buildings, Conventional Finite Element Analysis (CFEA) is typically adopted. However, CFEA is time consuming because of the large number of shell and frame elements required to model the SWP sheathing and studs. The SFEA proposed in this study consists of modeling each SWP in the building with an equivalent shell element of the same dimensions; that is, a complete SWP is modeled by a 16-node shell element. Thus, significantly fewer elements are required to model a building for SFEA compared to that required for CFEA, saving both time and resources. A model for the stiffness degradation of a SWP is developed as a function of the lateral strength of the SWP. The model characterizes the nonlinear behaviour of SWP under lateral loading, such that a realistic response of the building is achieved by the pushover analysis. The lateral strength of a SWP must be known before its seismic performance can be assessed. In current practice, the lateral strength of a SWP is primarily determined by experimental tests due to the lack of applicable analytical methods. In this investigation, an analytical method is developed for determining the ultimate lateral strength of SWP, and associated lateral displacement. The method takes into account the various factors that affect the behaviour and the strength of SWP, such as material properties, geometrical dimensions, and construction details. To illustrate the effectiveness and practical application of the proposed methodology for carrying out the PBD assessment of CFS buildings, several examples are presented. The responses predicted by the SFEA are compared with responses determined experimentally for isolated SWP. In addition, two building models are analyzed by SFEA, and the results are compared with those found by SAP2000 (2006). Lastly, the PBD assessment of two buildings is conducted using SFEA and pushover analysis accounting for the nonlinear behaviour of the SWP, to demonstrate the practicality of the proposed technology.
18

Seismic Performance Assessment of Multi-Storey Buildings with Cold Formed Steel Shear Wall Systems

Martinez Martinez, Joel January 2007 (has links)
Cold-Formed Steel (CFS) is a material used in the fabrication of structural and non-structural elements for the construction of commercial and residential buildings. CFS exhibits several advantages over other construction materials such as wood, concrete and hot-rolled steel (structural steel). The outstanding advantages of CFS are its lower overall cost and non-combustibility. The steel industry has promoted CFS in recent decades, causing a notable increase in the usage of CFS in building construction. Yet, structural steel elements are still more highly preferred, due to the complex analysis and design procedures associated with CFS members. In addition, the seismic performance of CFS buildings and their elements is not well known. The primary objective of this study is to develop a method for the seismic assessment of the lateral-load resistant shear wall panel elements of CFS buildings. The Performance-Based Design (PBD) philosophy is adopted as the basis for conducting the seismic assessment of low- and mid-rise CFS buildings, having from one to seven storeys. Seismic standards have been developed to guide the design of buildings such that they do not collapse when subjected to specified design earthquakes. PBD provides the designer with options to choose the performance objectives to be satisfied by a building to achieve a satisfactory design. A performance objective involves the combination of an earthquake (i.e., seismic hazard) and a performance level (i.e., limit state) expected for the structure. The building capacity related to each performance level is compared with the demand imposed by the earthquake. If the earthquake demand is less than the building capacity, the structure is appropriately designed. The seismic performance of a CFS building is obtained using pushover analysis, a nonlinear method of seismic analysis. This study proposes a Simplified Finite Element Analysis (SFEA) method to carry out the nonlinear structural analysis. In this study, lateral drifts associated with four performance levels are employed as acceptance criteria for the PBD assessment of CFS buildings. The lateral drifts are determined from experimental data. In CFS buildings, one of the primary load-resistant elements is Shear Wall Panel (SWP). The SWP is constructed with vertically spaced and aligned C-shape CFS studs. The ends of the studs are screwed to the top and bottom tracks, and structural sheathing is installed on one or both sides of the wall. For the analysis of CFS buildings, Conventional Finite Element Analysis (CFEA) is typically adopted. However, CFEA is time consuming because of the large number of shell and frame elements required to model the SWP sheathing and studs. The SFEA proposed in this study consists of modeling each SWP in the building with an equivalent shell element of the same dimensions; that is, a complete SWP is modeled by a 16-node shell element. Thus, significantly fewer elements are required to model a building for SFEA compared to that required for CFEA, saving both time and resources. A model for the stiffness degradation of a SWP is developed as a function of the lateral strength of the SWP. The model characterizes the nonlinear behaviour of SWP under lateral loading, such that a realistic response of the building is achieved by the pushover analysis. The lateral strength of a SWP must be known before its seismic performance can be assessed. In current practice, the lateral strength of a SWP is primarily determined by experimental tests due to the lack of applicable analytical methods. In this investigation, an analytical method is developed for determining the ultimate lateral strength of SWP, and associated lateral displacement. The method takes into account the various factors that affect the behaviour and the strength of SWP, such as material properties, geometrical dimensions, and construction details. To illustrate the effectiveness and practical application of the proposed methodology for carrying out the PBD assessment of CFS buildings, several examples are presented. The responses predicted by the SFEA are compared with responses determined experimentally for isolated SWP. In addition, two building models are analyzed by SFEA, and the results are compared with those found by SAP2000 (2006). Lastly, the PBD assessment of two buildings is conducted using SFEA and pushover analysis accounting for the nonlinear behaviour of the SWP, to demonstrate the practicality of the proposed technology.
19

Shear walls for multi-storey timber buildings

Vessby, Johan January 2008 (has links)
<p>Wind loads acting on wooden building structures need to be dealt with adequately in order to ensure that neither the serviceability limit state nor the ultimate limit state is exceeded. For the structural designer of tall buildings, avoiding the possibly serious consequences of heavy wind loading while taking account at the same time of the effects of gravitation can be a real challenge. Wind loads are usually no major problem for low buildings, such as one- to two-storey timber structures involving ordinary walls made by nailing or screwing sheets of various types to the frame, but when taller structures are designed and built, serious problems may arise.</p><p>Since wind speed and thus wind pressure increases with height above the ground and the shear forces transmitted by the walls increase accordingly, storey by storey, considerable efforts can be needed to handle the strong horizontal shear forces that are exerted on the bottom floor in particular. The strong uplift forces that can develop on the wind side of a structure are yet another matter that can be critical. Accordingly, a structure needs to be anchored to the substrate or to the ground by connections that are properly designed. Since the calculated uplift forces depend very much upon the models employed, the choice of models and simplifications in the analysis that are undertaken also need to be considered carefully.</p><p>The present licentiate thesis addresses questions of how wind loads acting on multi-storey timber buildings can be best dealt with and calculated for in the structural design of such buildings. The conventional use of sheathing either nailed or screwed to a timber framework is considered, together with other methods of stabilizing timber structures. Alternative ways of using solid timber elements for stabilization are also of special interest.</p><p>The finite element method was employed in simulating the structural behaviour of stabilizing units. A study was carried out of walls in which sheathing was nailed onto a timber frame. Different structural levels were involved, extending from modelling the performance of a single fastener and of the connection of the sheathing to frame, to the use of models of this sort for studying the overall structural behaviour of wall elements that possess a stabilizing function. The results of models used for simulating different load cases for walls agreed reasonably well with experimental test results. The structural properties of the fasteners binding the sheathing to the frame, as well as of the connections between the members of the frame were shown to have a strong effect on the simulated behaviour of shear wall units.</p><p>Regarding solid wall panels, it was concluded that walls with a high level of both stiffness and strength can be produced by use of such panels, and also that the connections between the solid wall panels can be designed in such a way that the shear forces involved are effectively transmitted from one panel to the next.</p>
20

Shear walls for multi-storey timber buildings

Vessby, Johan January 2008 (has links)
Wind loads acting on wooden building structures need to be dealt with adequately in order to ensure that neither the serviceability limit state nor the ultimate limit state is exceeded. For the structural designer of tall buildings, avoiding the possibly serious consequences of heavy wind loading while taking account at the same time of the effects of gravitation can be a real challenge. Wind loads are usually no major problem for low buildings, such as one- to two-storey timber structures involving ordinary walls made by nailing or screwing sheets of various types to the frame, but when taller structures are designed and built, serious problems may arise. Since wind speed and thus wind pressure increases with height above the ground and the shear forces transmitted by the walls increase accordingly, storey by storey, considerable efforts can be needed to handle the strong horizontal shear forces that are exerted on the bottom floor in particular. The strong uplift forces that can develop on the wind side of a structure are yet another matter that can be critical. Accordingly, a structure needs to be anchored to the substrate or to the ground by connections that are properly designed. Since the calculated uplift forces depend very much upon the models employed, the choice of models and simplifications in the analysis that are undertaken also need to be considered carefully. The present licentiate thesis addresses questions of how wind loads acting on multi-storey timber buildings can be best dealt with and calculated for in the structural design of such buildings. The conventional use of sheathing either nailed or screwed to a timber framework is considered, together with other methods of stabilizing timber structures. Alternative ways of using solid timber elements for stabilization are also of special interest. The finite element method was employed in simulating the structural behaviour of stabilizing units. A study was carried out of walls in which sheathing was nailed onto a timber frame. Different structural levels were involved, extending from modelling the performance of a single fastener and of the connection of the sheathing to frame, to the use of models of this sort for studying the overall structural behaviour of wall elements that possess a stabilizing function. The results of models used for simulating different load cases for walls agreed reasonably well with experimental test results. The structural properties of the fasteners binding the sheathing to the frame, as well as of the connections between the members of the frame were shown to have a strong effect on the simulated behaviour of shear wall units. Regarding solid wall panels, it was concluded that walls with a high level of both stiffness and strength can be produced by use of such panels, and also that the connections between the solid wall panels can be designed in such a way that the shear forces involved are effectively transmitted from one panel to the next.

Page generated in 0.09 seconds