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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

The structural response of submerged air-backed plates to underwater explosions

Hammond, Lloyd Charles, 1961- January 2000 (has links)
Abstract not available
52

The dynamic response of pile-soil interfaces during pile driving and dynamic testing events

Chin, Victor B. L January 2003 (has links)
Abstract not available
53

A force plate for measuring contact forces during dependent transfers onboard aircraft

Schafer, Christopher A. 15 March 2005 (has links)
The transfer of air travelers with disabilities between a mobility aid and an aircraft seat is a major source of injury for both the travelers and the airline personnel assisting in the transfer. The risk to both parties might be reduced through the biomechanical study of the transfer task. Such study requires that the contact forces acting on the body of the rear transferor be known, including the contact force between the rear transferor and the seat-back. A seat-back mounted force plate was designed and constructed to accurately measure the magnitude and the center of pressure location of normal forces applied to the seat-back. This force plate collects data from four preloaded single component force transducers. The force transducers are mechanically isolated from shear forces to protect them from damage. Testing of the force plate found a normal force magnitude accuracy of 0.19 %FS over the 890 Newton (200 lbf) calibrated range. The force plate was shown to have a horizontal and vertical center of pressure location accuracy of 2.66 and 1.58 millimeters (0.105 and 0.062 inches) RMS respectively over its 343 by 293 millimeter (13.5 by 11.5 inches) measurement range. By measuring forces that may have otherwise been ignored, the seat-back mounted force plate can improve the quality of the biomechanical analysis of aircraft transfers. / Graduation date: 2005
54

Wind Uplift Resistance of Roof Edge Components

Alassafin, Wassim 18 March 2013 (has links)
A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components. The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions. Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.
55

Modelling Effects Of Insufficient Lap Splices On A Deficient Reinforced Concrete Frame

Lin, Wesley Wei-chih 01 February 2013 (has links) (PDF)
assessed and strengthened. Performance evaluation of deficient buildings has become a major concern due to devastating earthquakes in the past. In order to justify new provisions in design and assessment codes, experiments and analyses are inherently necessary. In this thesis study, investigations into the behaviour of two deficient reinforced concrete frames built at Middle East Technical University&rsquo / s Structural and Earthquake Laboratory and tested via pseudo-dynamic tests were made. These frames were modelled on the OpenSees platform by following methods of analyses outlined in the Turkish Earthquake Code of 2007 (TEC 2007) and ASCE/SEI-41-06. Both deficient frames were essentially the same, with the only difference being the presence of insufficient lap splices, which was the focus of the study. Time history performance assessments were conducted in accordance to TEC 2007&rsquo / s damage state limits and ASCE/SEI 41-06&rsquo / s performance limits. The damages observed matched the performance levels estimated through the procedure outlined in TEC 2007 rather well. Specific to the specimen with lap splice deficiencies, ASCE/SEI 41-06 was overly conservative in its assessments. TEC 2007&rsquo / s requirements for lap splice lengths were found to be conservative in the laboratory and are able to tolerate deficiencies up to 25% of the required length. With respect to mathematical models, accounting for materials in deficient systems by using nominal but reduced strength properties is not very efficient and unless joint deformations are explicitly accounted for, local deformations cannot be captured.
56

Commissioning of the multi-use static/dynamic large-scale soil testing table

Stromberg, Michael Paul 30 October 2012 (has links)
This thesis presents the details of designing and commissioning the multi-use static/dynamic large-scale soil testing table. The table was developed with the intention of creating a large scale testing apparatus versatile enough to carry out several different types of testing on a large scale. This report describes the background research done to develop the testing table concept and the thinking that went into each component. The apparatus itself consists of a shake table with a laminar soil container (inside dimensions L:100cm W:50cm H:65cm) and a top which can be lowered to apply overburden pressures on specimens. It is set up to run both static and cyclic tests on large soil samples. The final design allows for performing shaking tests with a non-fixed top, static and dynamic simple shear tests, and direst shear tests with minimal changes to the table configuration. The table has separate control and data acquisition systems which are necessary to run and record tests. All components of the table will be explained thoroughly within the thesis. Preliminary testing was done with the table to determine how well it is functioning and what needs to be done to further improve it. Static simple shear and cyclic simple shear tests were both run, and while the table showed some flaws, the results seem promising. It is determined that with proper instrumentation and after addressing some small issues, the testing table can be a useful and versatile tool in the future. This thesis will outline the strengths and flaws of the table as currently constructed and determine what the future applications for this testing apparatus will be. / text
57

An experimental analysis of the dynamic failure resistance of TiB₂/A1₂O₃ composites

Keller, Andrew R. 12 1900 (has links)
No description available.
58

Partially restrained composite connections : design and analysis of a prototype structure

Kahle, Matthew Gilbert 12 1900 (has links)
No description available.
59

Wind Uplift Resistance of Roof Edge Components

Alassafin, Wassim 18 March 2013 (has links)
A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components. The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions. Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.
60

Numerical modelling of real-time sub-structure testing

Williams, David Michael January 2000 (has links)
Current dynamic testing methods can prove unrealistic due to the scale at which test components are modelled, the rate at which they are loaded or the boundary conditions to which they are subjected. A new test method, termed "Real-Time Sub-Structure Testing" seeks to provide a more realistic testing environment for energy dissipative components. The method tests structural components at full or large scale and in real-time. The physical test interacts with a computer model of the structure surrounding the test component. In this way, the in-situ behaviour of the test component is evaluated in relation to the overall structural response. The testing method requires fast and realistic modelling of the surrounding structure and a rapid interaction with the physical test specimen. For these reasons, a new non-linear finite element method has been proposed in order to model the surrounding structure behaviour efficiently. The method uses the Central Difference Method time stepping integration scheme together with a newly devised basis. The proposed basis consists of the structure’s elastic modes and additional Ritz vectors, which are calculated from the inelastic static displacement shapes of the structure. The displacement shapes correspond to the same static spatial distribution of loading as the intended dynamic excitation, and are intended to characterise the inelastic behaviour of the structure. The method has been validated against a Newmark event to event algorithm as well as Drain2DX. The non-linear dynamic response of a propped cantilever beam and portal frame structure was investigated. The response evaluated by the algorithm agrees closely with both validation analyses. The new algorithm was also shown to be faster than the Newmark procedure in simple benchmark tests. In addition, a numerical model of the testing apparatus has been developed in order to simulate complete tests for the purposes of testing procedure development and validation. The model is developed using Matlab Simulink. Parameters for the model are deduced from published data, experimental component tests and open loop step response calibrations. The model behaviour was found to be very sensitive to the parameters used. However, after calibration against open loop tests the model reproduces the observed laboratory behaviour to a good degree of accuracy. In an attempt to predict the behaviour of an actual test, the laboratory model has been coupled with the new structural solution algorithm to simulate a virtual test. The simulated results compare well with experimentally observed data demonstrating the usefulness of the overall simulation as a test modelling tool.

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