The United States has the world’s largest road network with over 4.1 million miles of roads supporting more than 260 million of registered automobiles including around 11 million of heavy trucks. Such a large road network challenges the road and traffic management systems such as condition assessment and traffic monitoring. To assess the road conditions and track the traffic, currently, multiple facilities are required simultaneously. For instance, vehicle-based image techniques are available for pavements’ mechanical behavior detection such as cracks, high-speed vehicle-based profilers are used upon request for the road ride quality evaluation, and inductive loops or strain sensors are deployed inside pavements for traffic data collection. Having multiple facilities and systems for the road conditions and traffic information monitoring raises the cost for the assessment and complicates the process. In this study, an integrated system is developed to simultaneously monitor the road condition and traffic using in-pavement strain-based sensors, which will phenomenally simplify the road condition and traffic monitoring. To accomplish such a superior system, this dissertation designs an innovative integrated sensing system, installs the integrated system in Minnesota's Cold Weather Road Research Facility (MnROAD), monitors the early health conditions of the pavements and ride quality evaluation, investigates algorithms by using the developed system for traffic data collection especially weigh-in-motion measurements, and optimizes the system through optimal system design. The developed integrated system is promising to use one system for multiple purposes, which gains a considerable efficiency increase as well as a potential significant cost reduction for intelligent transportation system. / USDOT (U.S. Department of Transportation) / MPC (Mountain-Plains Consortium)

Within the last ten years there has been much interest in the field of elasto-plastic behavior of engineering materials. Hie recent popularity of the low-cost light-weight plastically designed structures has added a great deal of impetus to this interest. This thesis deals with one of the aspects of elasto-plastic behavior, namely, the distribution of the residual stresses in a simple member which has been plastically deformed in tension and/or compression,. In particular, an attempt has been made to relate these residual stresses to the well-known but little understood Bauschinger effect.

In the usual thermal stress analysis of a body, the stresses are found for a predetermined temperature distribution. In problems involving composite materials, thermal contact resistance between materials can significantly affect the temperature distribution. The contact resistance is normally a function of the contact pressure and thermally induced stresses can affect the temperature distribution. Thus in composite bodies the thermal stress problem and the heat transfer problem may be coupled and require a simultaneous solution of both problems.

The object of this thesis was to lay a foundation for a comprehensive study of the dynamic response of rotating members. This initial phase of the study includes a theoretical investigation and proposes experimental techniques for the determination of the stresses and strains in a thin, rotating disk with a concentric hole, subjected to transient shaft inputs. There are many practical applications of this problem including computor memory storage disks, turbine rotors, grinding wheels, saw blades, gears, optical reflectors, and solar sails for space vehicles.

The behavior of anisotropic materials has been the object of much recent research® The high strength to weight ratio needed by aerospace structures has necessitated the use of exotic, composite materials which generally exhibit anisotropic behavior® These materials cannot be fully utilized unless analytical techniques are used which take maximum advantage of their anisotropic behavior.

The purpose of this thesis was to study the tensile-stress versus strain characteristics of vinyl plastic at various temperatures as a function of strain rate.

The advancement of modern technology has brought with It a demand upon the engineer for more thorough analysis techniques. This has been precipitated by the advent of missiles and space-craft that do not permit regular inspections to determine causes of failure, crack propagation, design weaknesses, etc. Thus, a more complete analytical work must be performed to facilitate a foreknowledge of reaction and performance of a particular design to its environment.

As new materials are developed, it is essential to study their mechanical properties experimentally. It is easy to find properties like ultimate strength, yield strength, hardness, etc., using standard techniques. It is not possible to observe the tensile behavior of materials at high strain rates using standard equipment. Plastics are often subjected to tensile loads at various rates of loading, such as when they are used to absorb impact.

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