Strength Analysis of Brittle Materials
Abstract
Fracture stresses in specimens of four commercial polycrystalline ceramics differing in each linear dimension by a factor of four or five were measured at room temperature under controlled conditions. Data obtained were analyzed with the aid of fractographic examinations for applicability of Weibull statistics. A central problem in attempting to use ceramic materials in demanding structural applications is uncertainty about the stresses to which they can be safely subjected. A ceramic rarely, if ever, exhibits a characteristic failure stress. This stress depends on the nature and distribution of microscopic flaws that intensify stress locally, and fracture initiates at a single 'worst' flaw when Griffith's criterion for crack instability is met. Within the basic framework, theories are available for treating effects of time, size, and stress distribution on failure stress. This paper reviews these theories, and discusses their use in specifying limiting stresses in designing structural members.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1977
- Accession Number
- ADA048188
Entities
People
- D. E. Niesz
- G. K. Bansal
- W. H. Duckworth
Organizations
- Battelle Memorial Institute