Residual Stress

Dr. Hayashi's title of Doctor of Engineering research is X-ray Study on Fatigue Fracture Behavior of Aluminium. In the research, effect of crystal orientation on fatigue crack initiation life, directionality of fatigue strength in cold-rolled aluminium, grain size dependence of fatigue strength and crack growth, effect of test temperature on fatigue strength, fatigue crack growth in cold-rolled and stretched aluminium, etc, were studied. When Dr. Hayashi was working at Mechanical Engineering Research Laboratory, Hitachi Ltd., he studied and developed fatigue crack initiation life prediction technology based on X-ray diffraction, life prediction technology for fatigue and creep combined condition by short crack observation, X-ray fractography technology, surface crack configuration determining technique based on electrical potential drop method, corrosion fatigue life prediction and fracture suppression technology, low and high cycle thermal fatigue crack initiation and growth behavior, residual stress measurement technology by neutron diffraction method.