Accession Number : AD0473410

Title :   TENSILE STRENGTH OF BRITTLE MATERIALS.

Descriptive Note : Final rept. 15 Jan 64-15 Jan 65,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s) : Sedlacek, R.

Report Date : AUG 1965

Pagination or Media Count : 28

Abstract : The tensile strength of an alumina body was investigated by using hydraulically expanded cylindrical test specimens, and the effect of stress rate, gauge volume, and static stress on the ultimate tensile strength was evaluated. Experimental results showed that the tensile strength of alumina is strongly dependent on stress rate but not on gauge volume. At higher stress levels the resistance of alumina to constant static stress is relatively low, but there is a stress level, approximately 18,000 psi, which can be sustained for long periods of time, and which does not lower the ultimate tensile strength of alumina. This stress level is reached at the rate of 4000 psi/sec and represents 60% of the average ultimate strength (29,640 psi) obtained at the same stress rate. Test specimens subjected for twenty-four hours to this static stress, and loaded subsequently to failure at a constant rate, showed the same ultimate tensile strength as specimens stressed directly to failure at the same rate. (Author)

Descriptors :   (*CERAMIC MATERIALS, TENSILE PROPERTIES), BRITTLENESS, CYLINDRICAL BODIES, STRESSES, ALUMINUM COMPOUNDS, OXIDES, LOADS(FORCES), HYDRAULIC EQUIPMENT.

Distribution Statement : APPROVED FOR PUBLIC RELEASE