AN EXPERIMENTAL STUDY OF THE WEIBULL VOLUME THEORY
Abstract
Using a gas-bearing tensile test facility, an experimental program was conducted to provide clarification of Weibull's volume effect theory. The facility provides uniaxial loading with a uniform tensile field thus permitting a study of the Weibull theory in its simplest form. The primary material used for this investigation was hot pressed alumina made by AVCO. Graphite was used to explore effects as a guide to the general program. As a result, quite useful data are available on the graphite as well as alumina. The program verified the general conclusions of the theory of decreasing strength and standard deviation with increasing volume, but a single set of material constants to describe the total results was not obtained. Criteria are presented that will assist in both material understanding and design with brittle materials with more confidence. Evidence indicates that sample sizes should include at least 60 coupons for an optimum analysis of material constants and as few as 10 coupons for some values such as average strength. Strength correlated with density and there was evidence that the fracture location, whether transgranular or in the grain boundaries, is dependent on grain size and/or the structure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1967
- Accession Number
- AD0815390
Entities
People
- C. D. Pears
- H. S. Starrett
Organizations
- Southern Research