Elastic Properties of Boron Suboxide and the Diametrical Compression of Brittle Spheres
Abstract
The room temperature elastic moduli of hot pressed boron suboxide were determined in the 0-16% porosity range using the resonant sphere technique. Results revealed that Poisson's ratio was constant in this range and that Young's and shear moduli followed Hasselman's semi-empirical relation with E sub o= 68.5 x 10 to the 6th power psi and A = 5.1. High speed photographs of diametrically compressed glass spheres indicate that fracture initiates near the center of the sphere. Also a stress analysis of such a sphere shows that the maximum tensile stress occurs near the center of the sphere. Therefore a new test for the tensile strength of brittle materials is suggested which is not influenced by surface defects. The tensile strength of boron suboxide was determined using the diametrical compression test and values approximately 25% lower than four point bend tests were obtained.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1973
- Accession Number
- AD0764355
Entities
People
- Daniel R. Petrak
- Robert Ruh
- William B. Shook
Organizations
- Air Force Research Laboratory