Estimation of the bi-modulus of materials through deformation measurement in a Brazilian disk test

A completely analytical experimental theory is developed to determine the elastic tensile modulus Et and the elastic compressive modulus Ec of materials simultaneously through the deformation and displacement measurement in the Brazilian disk loaded by a pair of radial concentrated forces. Based on the proposed test theory, there are totally four kinds of estimation methods proposed. Two groups of experimental data are used to validate the proposed test theory. The analysis indicates that the estimated Et and Ec of materials have high reliability when measured horizontal and vertical displacements on the diameters are used simultaneously. The measurement error of displacement results in that the estimated Et and Ec of materials follow the t location-scale distribution very well. The validation works indicate that the proposed test method is feasible and liable, and is convenient to determine the Et and Ec of materials simultaneously through the simple indirect tension test (the Brazilian disk test).

► An analytical experimental theory is developed to measure the bi-modulus of material. ► Elastic tensile/compressive modulus Et and Ec can be measured simultaneously. ► The deformation in the Brazilian disk needs to be measured in tests. ► The theory is validated by two sets of experimental data available. ► Sensitive and probabilistic analysis are performed for the developed theory.