Local strain accumulation in fatigue crack propagation process of Ti‐6Al‐4V alloy |
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| Authors: | S Ye J ‐G Gong S ‐T Tu X ‐C Zhang C ‐C Zhang |
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| Affiliation: | 1. Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China;2. AECC Commercial Aircraft Engine Co. Ltd, Shanghai Engineering Research Center for Commercial Aircraft Engine, Shanghai, China |
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| Abstract: | Fatigue crack growth behaviours of the titanium alloy Ti‐6Al‐4V, with two different microstructures, at different maximum stresses were identified by digital image correlation technique. Full‐field strains were monitored around fatigue cracks after consecutive cycles in fatigue crack growth experiments. Results indicated that the Ti‐6Al‐4V alloy with a bi‐modal microstructure had a better fatigue resistance than that with a primary‐α microstructure. Typical behaviours of small cracks and the evolution of multi‐scale fatigue cracks were clarified. The strain accumulations around the micro‐notch and fatigue crack increased with increasing number of load cycles. On the basis of von Mises strain mapping, it was found that crack growth rate could be characterized by crack‐tip plastic zone size. |
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| Keywords: | crack growth rate digital image correlation multi‐scale fatigue crack titanium alloy |
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