Application of the Brazilian Disc Test for Strength Measurements on Ceramic Green Bodies

This paper presents a numerical and experimental study on the mechanical behavior of plasma shocked rock. The dynamic tensile behavior of plasma shock treated Balmoral Red granite was studied under dynamic loading using the Brazilian disc test and the Split Hopkinson Pressure Bar device. Different heat shocks were produced on the Brazilian disc samples by moving the plasma gun over the sample at different speeds. Microscopy clearly showed that as the duration of the thermal shock increases, the number of the surface cracks and their complexity increases (quantified here as the fractal dimension of the crack patterns) and the area of the damaged surface grows larger as well. At the highest thermal shock duration of 0.80 seconds the tensile strength of the Brazilian disc sample drops by approximately 20%. In the numerical simulations of the dynamic Brazilian disc test, this decrease in tensile strength was reproduced by modeling the plasma shock induced damage using the embedded discontinuity finite element method. The damage caused by the plasma shock was modeled by two methods, namely by pre-embedded discontinuity populations with zero strength and by assuming that the rock strength is lowered and conform to the Weibull distribution. This paper presents a quantitative assessment of the effects of the heat shock, the surface microstructure and mechanical behavior of the studied rock, and a promising numerical model to account for the pre-existing crack distributions in a rock material.

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The mixed-mode fracture resistance of C 50/60 and its suitability for use in precast elements as determined by the Brazilian disc test and three-point bending specimens

Theoretical and Applied Fracture Mechanics ◽

10.1016/j.tafmec.2018.08.003 ◽

2018 ◽

Vol 97 ◽

pp. 108-119 ◽

Cited By ~ 12

Author(s):

Stanislav Seitl ◽

Petr Miarka ◽

Vlastimil Bílek

Keyword(s):

Fracture Resistance ◽

Mixed Mode ◽

Mixed Mode Fracture ◽

Mode Fracture ◽

Brazilian Disc ◽

Three Point Bending ◽

Brazilian Disc Test ◽

C 50 ◽

Precast Elements

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Comparative Study on the Test Method for Tensile Elastic Modulus of Rock Materials

Advances in Civil Engineering ◽

10.1155/2019/3161953 ◽

2019 ◽

Vol 2019 ◽

pp. 1-18

Author(s):

Yan Zhang ◽

Dawei Yu

Keyword(s):

Elastic Modulus ◽

Comparative Investigation ◽

Test Method ◽

Bending Test ◽

Brazilian Disc ◽

Rock Materials ◽

Brazilian Disc Test ◽

Test Operation ◽

Uniaxial Compressive Test ◽

Tensile Elastic Modulus

Rock material has different mechanical behaviors under compressive and tensile loading. Correspondingly, there are two types of elastic modulus: compressive elastic modulus Ec and tensile elastic modulus Et, respectively. To distinguish which indirect test methodology, including three-points bending test and Brazilian disc test, is more suitable to measure the tensile elastic modulus Et of rock materials, a series of uniaxial compressive test (UCT), direct tensile test (DTT), three-points bending test, and Brazilian disc test are performed for three typical types of rock: marble, granite, and sandstone. Comparative investigation on the reliability of measurement results of tensile elastic modulus Et is systematically conducted. Finally, it is found that Brazilian disc test could be a suitable method to measure tensile elastic modulus of rock materials, due to the excellent agreement with that measured by DTT and the simplicity of sample preparation, as well as test operation.

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