# Engineering Mechanics

Proceedings Vol. 32 (2026)

ENGINEERING MECHANICS 2026

Copyright © 2026 Institute of Thermomechanics of the Czech Academy of Sciences, Prague

 

Pavlas J., Slavík S., Růžička M., Mára V., Krčil J.
pages 101 - 104, full text

This study investigates fatigue damage in protective coatings and fatigue crack initiation in the substrate of the nickel-based superalloy ZhS6K, widely used in helicopter turboshaft engine turbine blades, within the framework of the damage tolerance principle. Despite its widespread use in service, the relationship between surface damage and subsurface fatigue crack development in ZhS6K has not been thoroughly investigated. The effect of coating degradation on the initiation and propagation of fatigue microcracks in the substrate material is analyzed and the damage tolerance methodology is implemented. A key contribution of this work is the identification of specific operational manoeuvres that produce high mechanical loads, leading to minor surface damage while causing major fatigue damage in the substrate. The proposed approach allows for an evaluation of blade damage that does not rely on complete load history data. This new approach can be generalized to other turbine blade materials and operating conditions.

Ownership of copyright in original research articles remains with the Authors, and provided that, when reproducing parts of the contribution, the Authors acknowledge and/or reference the Proceedings, the Authors do not need to seek permission for re-use of their material.

All papers were reviewed by members of the scientific committee.