Grant: Research Tools and Instruments - Category 1 (<$150,000)

BACKGROUND: Automotive industries are facing severe challenges to improve fuel efficiency and to reduce greenhouse gas emission. Weight reduction in vehicle body structure has become an important venue to address these challenges. A new paradigm for designing light-weight vehicle bodies has been developed. Such a design paradigm is based on the load-transferring capacity of the structure rather than the stresses. Such a capacity is characterized by a new mathematical measure, Load Path Index (U*). The U* design paradigm complements the traditional stress-based design, but adds a new dimension by considering the load-transferringefficiency. However, there are a number of fundamental issues yet to be addressed and the U* formulation has been restricted to special materials. In light of the high demand on the vehicle structure performance, and its potential for other machinery and structural design, fundamental research to solidify and to extend the theoretical basis of the U* design approach is paramount.RESEARCH PROGRAMS: The goals of the research program are to solidify the theoretical foundation of the U* concept and to extend it to more general engineering materials and structure. A physical experiment will be developed, for the first time, to validate the U* concept. The key challenge is to identify the load flow. Another challenge using the U* design concept is the presence of the residual stress caused during the manufacturing process, such as welding, which has significant effects on the load path. To explore such effects, it is crucial to provide information about the stress field and the material properties at the weld and the heat zone. UltraMARS is a non-destructive sensing device, which can provide the information critical to theproposed research program, and funding is requested here for purchasing an UltraMARS.SIGNIFICANCE: The automotive industry is crucial to Canada's economy. However, this sector is challenged due to stringent requirements on the fuel efficiency and environmental protection. The research can be a major advance in designing light-weight vehicle body structure, which is vital to meet those requirements.