Modification of the least-squares method for description of fatigue crack propagation

• Autorzy: Kłysz S. , Lisiecki J. , Bąkowski T.
• Języki publikacji: EN

Abstrakty

EN

The paper presents the results obtained after modification of the least-squares method (LSM) intended to improve the correlation between the NASGRO equation and description of fatigue crack growth da/dN. In particular, the modification refers to all the cases when data approximation is to be carried out and value of one variable substantially differs (e.g. by several magnitude orders) from the range of values adopted by other variables. The attention is focused on illustrating the impact of individual parameters onto the course and possibility to match the aforementioned equation to experimental data. Due to high flexibility for description of experimental functions da/dN=f(deltaK) the NASGRO equation can be widely applied in practice and is deemed as the best tool to describe the foregoing relation.

Słowa kluczowe

EN

NASGRO equation; least squares method; crack propagation; curve-fit fatiguecrack growth data

• Wydawca: Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Prace Naukowe Instytutu Technicznego Wojsk Lotniczych
• Rocznik: 2010
• Tom: nr 27
• Strony: 85--91
• Opis fizyczny: Bibliogr. 5 poz., rys.

Twórcy

autor

Kłysz S.

autor

Lisiecki J.

autor

Bąkowski T.

• Air Force Institute of Technology

Bibliografia

• 1. AFGROW Users Guide And Technical Manual, AFRL-VA-WP-TR-2002-XXXX, Version 4.0005.12.10, James A. Harter, Air Vehicles Directorate, Air Force Research Laboratory, WPAFB OH 45433-7542.
• 2. ASTM E647 Standard test method for measurement of fatigue crack growth rates.
• 3. Fuchs H.O., Stephens R.I.: Metal fatigue in engeneering. A Willey-Interscience Publication, 1980.
• 4. Kłysz S.: Rozwój pęknięć zmęczeniowych w materiałach lotniczych i stali konstrukcyjnej z uwzględnieniem przeciążeń. Wydawnictwo ITWL, Warszawa 2001.
• 5. NASGRO® Fracture Mechanics and Fatigue Crack Growth Analysis Software, v5.0, NASA-JSC and Southwest Research Institute, July 2006.