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Volume 08
Research & Reviews: Journal of Engineering and Technology
ISSN: 2319-9873
Automobile Europe 2019
July 08-09, 2019
6
th
International Conference and Exhibition on
July 08-09, 2019 | Zurich, Switzerland
Automobile & Mechanical Engineering
An integrated approach to low-cycle/thermo mechanical fatigue design for automobile exhaust materials/
components
Xijia Wu
Aerospace Research Center-National Research Council, Canada
W
ith stringent environmental regulations and lightweight/fuel economy demands, advanced automobile exhaust
system design relies on utilization of materials to its maximum capacity against low- cycle fatigue (LCF)
and thermo mechanical fatigue (TMF) failure. Traditionally, characterization of material’s LCF/TMF resistance was
obtained through extensive testing and correlation, which drives the cost up for design. An integrated creep-fatigue
theory (ICFT) has been developed at the National Research Council, Canada, to address constitutive modelling and
life prediction, in a self-consistent and unified fashion, based on i) deformation decomposition by participating
mechanisms and ii) holistic damage accumulation by nucleation and propagation of surface/subsurface cracks in
coalescence with internally distributed damage. Automotive exhaust system materials such as ductile cast iron and
austenitic cast steel are used as example materials for demonstration in good agreement with experimental results
and metallurgical examinations. This enlightens the understanding of the roles each mechanism plays in LCF/TMF
processes, thus helping material and component design specifically targeting the most damaging mechanism(s)
encountered in service.
Xijia.wu@nrc-cnrc.gc.caJET 2019, Volume 08