Institute of Physics of Materials AS CR, v. v. i. > Projects > Oxide-induced crack closure and its implications for lifetime prediction of mechanical components (OXILAP)

Oxide-induced crack closure and its implications for lifetime prediction of mechanical components (OXILAP)

Investigatordoc. Ing. Pavel Hutař, Ph.D.
Number of Project22-28283S
AgencyGrantová agentura České republiky
Duration2022-01-01 - 2028-06-11

Anotace
The impact of oxide-induced crack closure (OICC) on a fatigue crack propagation threshold will be studied. The oxide formation on new crack surfaces significantly influences crack closure and is also responsible for differences in measured threshold values for given material. While it is known that even a slight change of the threshold has a major impact on estimated fatigue lifetime of the structure. The importance of the OICC in the different materials will be determined by studying both the dynamics of oxidation and the separation of the acting crack closing mechanisms. Separation of the OICC will be achieved by an original experimental procedure which make it possible measurement in dry air. Its influence will be further determined by measurement of the oxide layer formed during near-threshold loading using our methodology based on a focused ion beam cuts. More accurate mathematical models of crack closure during fatigue crack propagation will be developed to significantly refine the determination of fatigue life of structures loaded by variable load.