Authors:
Markus Schneider (GKN Sinter Metals Engineering GmbH, Germany),
Christos Radis (GKN Sinter Metals Engineering GmbH, Germany),
Robert Maassen (GKN Sinter Metals Engineering GmbH, Germany)
Abstract:
The Kitagawa-Takahashi approach combines two different reliability concepts. In classical high cycle fatigue testing the material is assumed as undamaged and the testing itself is responsible for the crack initiation. Depending on the failure criterion, very often defined as drop of the stiffness or resonance frequency, the subsequent crack propagation phase is not investigated. Crack propagation experiments by means of da|dN curves continue the testing in the damaged condition. If both reliability concepts are combined, a critical defect size can be defined. This critical defect size is of major importance since it defines the limit resolution of non-destructive testing methods. The loading ratio affects both testing procedures, e.g. over crack closure|opening effects and must be examined carefully. A typical sintered alloy was chosen for that study due to its large range of application. The derived critical defect sizes were compared with the maximum apparent 2D pore sizes.
DOI:
https://doi.org/10.59499/WP225369531