• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 23
  • 23
  • 16
  • 10
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
21

Performance Of Mechanical And Non-mechanical Connections To Gfrp Components

Dike, Nnadozie N 01 January 2012 (has links)
There are presently many solutions to dealing with aging or deteriorated structures. Depending on the state of the structure, it may need to be completely over-hauled, demolished and replaced, or only specific components may need rehabilitation. In the case of bridges, rehabilitation and maintenance of the decks are critical needs for infrastructure management. Viable rehabilitation options include replacement of decks with aluminum extrusions, hybrid composite and sandwich systems, precast reinforced concrete systems, or the use of pultruded fiber-reinforced polymer (FRP) shapes. Previous research using pultruded glass fiber-reinforced polymer (GFRP) decks, focused on behaviour under various strength and serviceability loading conditions. Failure modes observed were specific to delamination of the flexural cross sections, local crushing under loading pads, web buckling and lip separation. However certain failure mechanisms observed from in-situ installations differ from these laboratory results, including behaviour of the connectors or system of connection, as well as the effect of cyclic and torsional loads on the connection. This thesis investigates the role of mechanical and non-mechanical connectors in the composite action and failure mechanisms in a pultruded GFRP deck system. There are many interfaces including top panel to I-beam, deck panel to girder, and panel to panel, but this work focuses on investigating the top panel connection. This is achieved through comparative component level shear, uplift, and flexure testing to characterize failure and determine connector capacity. Additionally, a connection of this GFRP deck system to a concrete girder is investigated during the system-level test. Results show that an epoxy non-mechanical connection may be better than mechanical options in ensuring composite behaviour of the system.
22

Quality assessment of glass reinforced plastic ship hulls in naval applications / Glass reinforced plastic ship hulls in naval applications, Quality assessment of / Plastic ship hulls in naval applications, Quality assessment of glass reinforced

Thomas, Ronald David., Cable, Christopher Wheeler. January 1985 (has links)
Thesis: M.S., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 1985 / Includes bibliographical references. / by Ronald David Thomas and Christopher Wheeler Cable. / M.S. / M.S. Massachusetts Institute of Technology, Department of Materials Science and Engineering
23

Flexural Behavior of Laterally Damaged Full-Scale Bridge Girders Through the Use of Carbon Fiber Reinforced Polymers (CFRP)

Alteri, Nicholas James 01 January 2012 (has links)
ABSTRACT The repair and strengthening of concrete bridge members with CFRP has become increasingly popular over recent years. However, significant research is still needed in order to develop more robust guidelines and specifications. The research project aims to assist with improving design prosedures for damaged concrete members with the use of CFRP. This document summarizes the analysis and testing of full-scale 40’ foot long prestressed concrete (PSC) bridge girders exposed to simulated impact damage and repaired with carbon fiber reinforced polymers (CFRP) materials. A total of five AASHTO type II bridge girders fabricated in the 1960’s were taken from an existing bridge, and tested at the Florida Department of Transportation FDOT structures lab in Tallahassee, Florida. The test specimens were tested under static loading to failure under 4-point bending. Different CFRP configurations were applied to each of the girders. Each of the test girders performed very well as each of them held a higher capacity than the control girder. The repaired girders 5, 6 and 7 surpassed the control girder’s capacity by 10.88%, 15.9% and 11.39%. These results indicate that repairing laterally damaged prestressed concrete bridge girders with CFRP is an effective way to restore the girders flexural capacity.

Page generated in 0.1197 seconds