Modelling the Transition from Channel-Veins to PSBs in the Early Stage of Fatigue Tests
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Thu, 26/01/2012 16:00 |
Yichao Zhu (Oxford) |
Industrial and Applied Mathematics Seminar  |
DH 1st floor SR |
| Understanding the fatigue of metals under cyclic loads is crucial for some fields in mechanical engineering, such as the design of wheels of high speed trains and aero-plane engines. Experimentally it has been found that metal fatigue induced by cyclic loads is closely related to a ladder shape pattern of dislocations known as a persistent slip band (PSB). In this talk, a quantitative description for the formation of PSBs is proposed from two angles: 1. the motion of a single dislocation analised by using asymptotic expansions and numerical simulations; 2. the collective behaviour of a large number of dislocations analised by using a method of multiple scales. | |||