Accession Number:

AD0752054

Title:

Dynamic Tensile Failure in Rocks

Descriptive Note:

Semiannual technical rept. 15 Apr-15 Oct 1972

Corporate Author:

STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s):

• Shockey, Donald A.

Report Date:

1972-10-30

Pagination or Media Count:

32.0

Abstract:

A fracture model is being developed based on the hypothesis that dynamic tensile failure in rocks occurs by the activation of preexisting flaws which propagate and may coalesce to produce fragments of various size. During the previous year the first two stages of the fracture process--flaw activation and crack growth--were treated quantitatively. The fracture model in its present stage of development allows us to predict the number of cracks, the total fracture surface area, and the energy absorbed by creation of new surface resulting from a known dynamic loading history. Although the model is not complete, procedures to generalize the fracture model to other rocks were initiated by examining petrographically specimens of Sioux quartzite, Westerly granite, and pink Tennessee marble to attempt to reveal and describe quantitatively their inherent flaw structures.

Descriptors:

• *ROCK
• CRACKS
• DEFECTS(MATERIALS)
• FRACTURE(MECHANICS)
• GRANITE
• LOADS(FORCES)
• METAMORPHIC ROCK
• MICROSTRUCTURE
• PETROGRAPHY
• QUARTZ
• TENSILE PROPERTIES

Subject Categories:

• Geology, Geochemistry and Mineralogy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE