GCOE Seminars

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2011/12/27

13:30-14:30   Room #370 (Graduate School of Math. Sci. Bldg.)
Yichao Zhu (University of Oxford)
The Modelling of Dislocations in the Early Stage of the Metal Fatigue (ENGLISH)
[ Abstract ]
Understanding fatigue of metal under cyclic loads is crucial for some fields in mechanical engineering, such as the design of wheels of high speed trains and the aeroplane engine. Experimentally it has been found that this type of
fatigue is closely related to a ladder shape pattern of dislocations known as a persistent slip band (PSB) at a microscopic level. In this talk, a quantitative description for the formation of PSBs is proposed from two angles: 1. the motion of a single dislocation analysed by using asymptotic expansions and numerical simulations; 2. the collective behaviour of a large number of dislocations analysed by using a method of multiple scales.