Refined Test Methods in Evaluating Brittle Material Fracture Strengths
NORTH CAROLINA AGRICULTURAL AND TECHNICAL STATE UNIV GREENSBORO SCHOOL OF ENGINEERING
Pagination or Media Count:
This report is a follow-up of the work done under the previous contract, entitled,Fracture Prediction in Brittle Materials. In the former contract, an analytical system was devised to generate fracture data based on 1 conversion of triaxial fracture data to a single variable, phi, the angle on the fracture surface from point of fracture to the n1,1,1 direction, 2 the creation of a simple test procedure and specimen design to find a variety of points on the fracture surface, and 3 the design of experiments to employ this testing system. In the first contract, both alumina and mullite specimens were tested in four-point loading and these results were reduced to a Weibull distribution by determination of the two-parameter coefficients. In this contract, a torsion test method and apparatus were designed and implemented. Both alumina and mullite specimens, the same geometry as was used in the four- point bend test of the previous contract were loaded in torsion to failure at another angle on the fracture surface, or at phi 90 degs to the n1,1,1 direction. The results are given for alumina and mullite tests. Finally, a general test utilizing thick disks of each material is described.
- Ceramics, Refractories and Glass