Institute of Physics of Materials AS CR, v. v. i. > Projects > Description of short fatigue crack growth in large scale yielding conditions

Description of short fatigue crack growth in large scale yielding conditions

Investigatorprof. Mgr. Tomáš Kruml, CSc.
Number of Project18-03615S
AgencyGrantová agentura České republiky
Duration2018-01-01 - 2020-12-31

Anotace
The prediction of residual fatigue life of structures or components with cracks requires knowledge about the crack growth rate. Theory and experimental procedures for the measurement of the crack growth rate in the small scale yielding conditions at the crack tip is well established. However, the kinetics of crack growth rate in condition of a non-negligible plasticity around the crack tip has been studied to much lesser extent. Recently, a large set of short fatigue crack growth rate data measured in the applicant’s laboratory were reanalysed. This comparison revealed that the plastic part of the J-integral (and not the total J-integral) is the parameter governing the short crack growth rate in large scale yielding conditions. Moreover, crack growth rate data from all analysed materials lie on a unique curve. This remarkable observation suggests that the crack growth rate is determined by the extent of energy spent to plastic deformation at the crack tip, irrespective of the other materials properties. In this project, we want to critically assess this hypothesis.


2020

Polák J., Petráš R.: Cyclic plastic response and damage mechanisms in superaustenitic steel Sanicro 25 in high temperature cycling - Effect of tensile dwells and thermomechanical cycling. Theor. Appl. Fract. Mech. 108 (2020) 102641

Chlupová A., Poczklán L., Man J., Mazánová V., Heczko M., Kruml T.: Character of Fatigue Damage under Axial, Torsional and Biaxial Loading of 316L Stainless Steel. Defect Diffus. Forum 405 (2020) 264-270

Polák J.: Production, annihilation and migration of point defects in cyclic straining. Materialia 14 (2020) 100938

Petráš R., Šulák I., Polák J.: The effect of dwell on thermomechanical fatigue in superaustenitic steel Sanicro 25. Fatigue Fract. Eng. Mater. Struct. 2020 (2020) 1-16



2019

Oplt T., Hutař P., Pokorný P., Náhlík L., Chlup Z., Berto F.: Effect of the free surface on the fatigue crack front curvature at high stress asymmetry. Int. J. Fatigue 118 (2019) 249-261

Oplt T., Šebík M., Berto F., Náhlík L., Pokorný P., Hutař P.: Strategy of plasticity induced crack closure numerical evaluation. Theor. Appl. Fract. Mech. 102 (2019) 59-69

Mazánová V., Heczko M., Škorík V., Chlupová A., Polák J., Kruml T.: Microstructure and martensitic transformation in 316L austenitic steel during multiaxial low cycle fatigue at room temperature. Mater. Sci. Eng. A 767 (2019) 138407

Oplt T., Hutař P., Pokorný P., Náhlík L., Berto F.: Numerical evaluation of plasticity induced crack closure in 3D structures. Procedia Struct. Integr. 23 (2019) 101-106