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:
More and more engineering practice indicates rock mass is prone to lose its stabilitythrough crack coalescence under dynamic loading, such as blasting and earthquake. However, thecrack coalescence pattern of rock specimens containing two or more flaws has not been studiedcomprehensively under dynamic loading. In this paper, the mechanism of the crack coalescence andpeak strength of sandstone-like materials containing two parallel flaws are studied under uniaxialstatic and dynamic loading with strain rates 1.7×10-5 s-1 and 1.7×10-1 s-1. Through the comparisons ofthe propagation length, coalescence pattern of the cracks and strength increase of the pre-crackedspecimens under static and dynamic loading, the dynamic response of the crack coalescence is founddifferent from static loading under different geometric setting of the flaws. The inertia effect of thecrack propagation is revealed under dynamic loading, that is to say, the growth of the secondarycracks tends to the original propagation direction, and the direct and immediate coalescence is takenplace easily between two pre-existing flaws, which is different from the kinking coalescence understatic loading. So, the inertia effect of the crack propagation is regarded as the main cause of thestrength increase of the brittle material under dynamic loading for medium strain rates. In virtue of theexplanation, another cause of the mode II shear fracture occurred under earthquake is opened out
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.324-325.117.pdf
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