Determination of Tensile Elastic Parameters from Brazilian Tensile Test: Theory and Experiments

Abstract

Elastic properties of rocks, including Young’s modulus and Poisson’s ratio, are usually obtained from the uniaxial compressive strength (UCS) test, while tensile strength is obtained from direct or indirect (Brazilian) tensile test. In this paper, we developed an analytical model as well as an improved test procedure, called modified Brazilian tensile (MBT) test, which can simultaneously measure the tensile strength, Young’s modulus and Poisson’s ratio in a single test by attaching two strain gauges at the center of each end face of the specimen. To validate the proposed model, both the UCS and modified Brazilian tensile tests were conducted using two types of aluminum alloy (AL 6061 and AL 7075). Results showed that the Young’s modulus obtained from UCS tests and MBT tests are within the range of experimental error. Poisson’s ratios determined from the two test methods were consistent. The proposed model was further validated with Colton sandstones. The Young’s modulus and the Poisson’s ratio obtained from the UCS test and the MBT test agreed well. We also conducted numerical modeling for further comparison, and the results also verified the reasonableness of the proposed model.