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:
The crack propagation along the bond coat / topcoat interface of a TBC system has been studied in a previous work under a certain mode ratio (K〈sub〉〈/sub〉2/K〈sub〉〈/sub〉1). In order to discuss a parameter thatdescribes the crack propagation, the growth behavior of a crack has to be studied under various K〈sub〉〈/sub〉2/K1 ratios. In this work, BEM was used to determine the modifications that change K〈sub〉〈/sub〉2/K〈sub〉〈/sub〉1 ratios of the specimen employed in the previous study. Six characteristics of the specimen were modified: location of the applied load; height; length, position and direction of the notch, and itsseparation from the bond coat / topcoat interface. Among these modifications, the change of location of load point can effectively change K〈sub〉〈/sub〉2/K〈sub〉〈/sub〉1 ratio to values greater and smaller than those of the previous study.Crack propagation tests with three different positions of load point were performed usingspecimens with topcoat porosity of 5%, 15% and 20%. The results indicated that, independently of K〈sub〉〈/sub〉2/K〈sub〉〈/sub〉1 ratio, the parameter K〈sub〉〈/sub〉i dominated the crack growth behavior for an interface crack undermixed mode
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/47/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.261-263.441.pdf
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