ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
This paper is concerned with the premature failures occurred in the high pressure compressorsection of the gas turbine of HESA power plant in Iran. Metallurgical and mechanical properties ofthe blade alloy were evaluated. Fractography investigations were carried out on the fracture surfaceof the blade roots using scanning electron microscopy. Stress and fracture simulations wereconducted using ANSYS software in both 2D and 3D dimensions under centrifugal, aerodynamicand contact forces. The aerodynamic forces were evaluated using FLUENT software.The results showed no metallurgical and mechanical deviations for the blade material fromstandards. SEM fractography showed different aspects of fretting fatigue including multiple crackinitiation sites, fatigue beach marks, debris particles, and a high surface roughness on the edge ofcontact (EOC). The simulation results showed that there was a high stress gradient at the EOC ofthe blade which is one of the most significant characteristics of the fretting fatigue. Another analysiswas performed to simulate the fracture by creating an initial crack on the EOC. The stress fields andstress intensity factors for modes I, II and III were evaluated along the crack front. The resultsindicated a strong stress intensity factor for mode I at the EOC
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.385-387.401.pdf
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