Residual stresses measurements with X-ray diffractometry on aluminum specimens - determination of the most suitable parameters of measurement

• Autorzy: Gadalińska E. , Kaniowski J.
• Języki publikacji: EN

Abstrakty

EN

The work was done as apart of the IMPERJA Eureka Project. The goal of the IMPERJA project is to increase the fatigue life of riveted joints, which will lead to an increase of the aircraft service life, a smaller number of inspections and lower operation costs of an aircraft. The consortium intends to meet this goal by investigating and improving the riveting process as well as improving the prediction methods for fatigue life. Riveting is the most commonly used method of joining sheet metal components of the aircraft structure. Typically, the number of rivets ranges from several thousands to some millions in a single aircraft depending on the specific aircraft type and size. The riveted joints are critical areas of the aircraft structure due to severe stress concentrations and effects such as fretting and secondary bending. Therefore the fatigue crack initiation will start at the rivets holes. Fatigue crack initiation usually occurs at a number of rivet holes (multiple site damage), which may lead to widespread fatigue damage and reduced residual strength. Although the literature on the fatigue behaviour of riveted joints is quite abundant, many aspects are still not sufficiently understood and investigated and, therefore, they require a further study. The work contains the results of stress measurements obtained with X-ray diffractometer. The aim of the work was to determine the stress values after different kinds of treatment, to check what are the limits of the x-ray measurement for aluminum alloys and to obtain the most suitable measurement parameters for this kind of alloy. There were 5 kinds of specimens: -specimen no. l - technically pure aluminum, specimen annealed in temperature 300° C for l hour, -specimen no. 2 - technically pure aluminum, raw state without any additional treatment, -    -specimen no. 3 - technically pure aluminum, squeezed perpendicularly to the axis direction, force: l00 kN, longitudinal intersection, specimen no. 4 - technically pure aluminum, squeezed perpendicularly to the axis direction, force: 100 kN, transverse intersection, specimen no. 5 - PA24 alloy, 05 bar, squeezed along the axis of the rod, force: l3,9 kN, longitudinal intersection. The second part of the work contains the measurements of the stress distribution around the rivets. The specimen prepared to realize this kind of measurements had four areas. The rivets on every area were riveted with the different riveting force: 1.2 kN; 1.4 kN; 1.5 kN and 1.55 kN.

Słowa kluczowe

EN

X-ray diffractometry; residual stresses; fatigue; aluminum alloys

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2009
• Tom: Vol. 16, No. 4
• Strony: 123--134
• Opis fizyczny: Bibliogr. 4 poz., rys.

Twórcy

autor

Gadalińska E.

autor

Kaniowski J.

• Institute of Aviation Krakowska Av. 110/114, 02-256 Warsaw tel: [phone] ext. 543, 541,fax: [phone],

Bibliografia

• [1] Cullity, B. D., Podstawy dyfrakcji promieni rentgenowskich, Państwowe Wydawnictwo Naukowe, wyd. I, Warszawa 1964.
• [2] Metallography and Microstructures, ASM Handbook, Volume 9, 2004.
• [3] Properties and selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook,Volume 2:0
• [4] Gadalińska, E., Pomiar naprężeń własnych w próbkach z aluminium technicznego oraz stopu PA24 przy różnych stopniach spęczenia, wewnętrzne sprawozdanie ILot nr GR/0005/BP/2009, Instytut Lotnictwa 2009.