Brazilian tests were carried out to determine size-tensile strength dependence in dacite, Valders limestone, and St. Cloud gray granodiorite. It was concluded that there is a size effect on tensile strength; in Brazilian test, this effect is governed mainly by the position and orientation of the internal flaws relative to the loaded diametral plane. A two-dimensional computer program simulating the Brazilian test was written. The program employs four-sided, isoparametric elements and is based on the same failure criteria used in the first annual progress report. The present program, however, is more efficient and contains several features not found in the first program. Test runs have proven that the program can predict accurately the progression of failure in Brazilian test and, to a lesser extent, the correlation of load and displacement.
