The research activities in the high cycle fatigue group are focused on the study of the nature and quantitative description of the fatigue processes in all fatigue stages. The main goal of the research is to contribute to better understanding of cyclic plasticity at low amplitudes, crack initiation and threshold values of fatigue crack propagation and to the fracture-mechanical description of the fatigue crack behaviour. Theoretical and experimental studies are focused on the relation between microstructure, microstructure evolution during damage progress, and macroscopic fatigue and fatigue/creep properties. The numerical estimation of the fracture parameters and simulations of the fracture behaviour are an important part of the research as well. The formulation of crack stability criteria for non-homogenous materials, notches and layered structures is a live issue studied in the group. Owing to this, the spectrum of studied materials is rapidly increasing. At present non-metallic materials such as polymers, polymer or ceramic based composites and advanced building materials are also dealt with.
In close cooperation with some industrial companies, the lifetime of advanced components is predicted based on numerical simulations and advanced fatigue tests.
The research of fatigue phenomena started at the IPM under the leadership of Prof. Mirko Klesnil in the 1960s. From the mid 1980s to 2010 the head of the high cycle fatigue group was assoc. Prof. Petr Lukáš, a well-known expert in the field of basic mechanisms of fatigue. The theoretically and computationally oriented part of the research group was established in the 1980s by Prof. Zdenìk Knésl, who was a natural and respected supervisor. The present staff of the group can be found here.
The main research projects currently running:
- fatigue and fatigue/creep behaviour of single crystalline and polycrystalline superalloys,
- fatigue properties of ultrafine-grained materials,
- effect of mean stress on the cyclic stress-strain response and fatigue life,
- effect of notches (including bi-material notches) and cracks on fatigue life and fatigue/creep life,
- effect of a free surface on fatigue crack behaviour,
- physical consequences of the constraint,
- effect of the interface between two materials on a crack or notch behaviour,
- basic fatigue and fracture characteristics of advanced building materials,
- description of the crack behaviour in polymer materials,
- description of the crack behaviour in advanced composite materials.