No description available.

No description available.

In response to global climate change, Transport Canada has initiated a Climate Change Adaptation Study in order to provide an opportunity to improve knowledge of the impacts of climate change on transportation infrastructure in Northern Canada. In particular, this research aims to identify ways to mitigate the impacts of climate change on pavement surface friction characteristics at a project specific location: Runway 07-25 of Kuujjuaq Airport in Nunavik, Québec. This site was chosen because it is a complex site with highly variable soil conditions. Runway 07-25 is one of the busier runways in Nunavik and its traffic includes jet airplanes. The runway is also exposed to extensive winter maintenance activities. In addition, Runway 07-25 is considered a short runway and has a crossfall instead of crown for surface drainage. Increasing ambient temperatures have already led to a deeper active layer over permafrost, which affects overall runway performance. Climate change is especially evident in the winter months with large temperature fluctuations resulting in increased freeze thaw cycles. The site is, therefore, a good location to study solutions to climate change impacts, which are expected to affect other Canadian airports in the future. Kuujjuaq Runway 07-25 is of paramount importance to the community of Kuujjuaq, other communities in Nunavik, and communities north of Nunavik. It serves as a regional hub between the south, Nunavik’s communities and Iqaluit to the north, and provides an essential link for emergency evacuations, personal and business travel, as well as the transportation of basic food items. Globally, amongst the groups, the most affected by the impacts of climate change are the Inuit communities in Nunavik. Scientists and residents of these communities are witnessing growing evidence of the impacts of accelerated warming in this region, which is expected to continue into the future. In this research, runway texture and friction are assessed on Runway 07-25, as increased winter maintenance activities resulting from climate change are thought to be reducing surface friction. Existing friction and texture measurement data from previous years, current laboratory testing results on samples of the existing asphalt concrete mix as well as current surface texture and friction measurement data from the runway have been analysed to study trends and characterize the runway in terms of its frictional resistance. Friction improving technologies/products are discussed for maintenance and future rehabilitation options.

No description available.

This study addresses a range of phenomena associated with dry frictional contacts. Particular emphasis is devoted to elastic dissimilarity. Problems are formulated such that coupling between normal and tangential tractions is permitted and the results, which must often be found by numerical means, are compared with classical solutions. The manipulation of objects in contact with frictional surfaces is investigated. The main focus is on objects resting upon a plane at three discrete points of support. When displaced by an arbitrary force such objects have a tendency to rotate about these points of support. The motion of both planar and three dimensional objects is predicted and the effect of friction at the pushing contact is considered. Rolling contact between two elastically dissimilar cylinders is addressed. By allowing full coupling between normal and tangential tractions it is found that an offset in the contact patch may result. This often leads to a significant resistive moment which balances the nett power supplied and the frictional losses. Three dimensional contacts form a major part of the study and a numerical method is developed to facilitate their solution. The evolution of an incomplete contact is evaluated to demonstrate how contact boundaries may be determined. The method is then applied to sliding contact between elastically dissimilar spheres. The traction distributions which result from a fully coupled formulation are compared with those predicted by a Hertzian solution. The parameters which cause the greatest differences are found. A Mindlin-type contact is re-evaluated and traction distributions are calculated which are compatible with local slip directions for both elastically similar and dissimilar bodies. A comprehensive set of results is presented revealing how material parameters influence the solution. Interactions between cracks and contacts are analyzed. It is shown that although the change in compliance of a flawed body may modify the traction distribution compared with a flawless one, the stress intensity factors at the crack tip are rarely affected. Finally, a method of determining the fracture toughness of brittle materials is explored based on the observation of surface cracks in the wake of a sliding indenter. Material characteristics are related to crack initiation, spacing and depth.

Thesis (Ph.D.)--Tennessee Technological University, 2007. / Bibliography: leaves 71-75.

Thesis (M.S.)--Ohio University, June, 1989. / Title from PDF t.p.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [114]-116).

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xxiv, 200 p.; also includes graphics (some col.). Includes bibliographical references (p. 196-200). Available online via OhioLINK's ETD Center

Thesis (M.S.)--Oregon State University, 1977. / Includes bibliographical references (p. 83-84). Also available on the World Wide Web.