PSI - Issue 6

A. Martemyanov et al. / Procedia Structural Integrity 6 (2017) 336–343 A. Martemyanov et al. / Structural Integrity Procedia 00 (2017) 000 – 000

340

5

Fig. 3.Incubation time criterion application for united Laurentian granite dynamic tensile tests data.

Process of different techniques results comparison may be developed for deep understanding of static strength and incubation time role in the material destruction under dynamic conditions. This problem requires detailed understanding of stress history at given point before fracture appears.

3.2. Barre granite dynamic tests results. Anisotropic case.

Rocks are often anisotropic and it is should be expected that dynamic characteristics will depend on orientation. Barre granite tensile strength was measured with the help of Brazilian test in both static and dynamic cases (Dai and Xia (2010)). Test samples were divided to six groups with different orientation and in this work uses original nomenclature which imaged on figure 4a. For whole data set bordering incubation time values was estimated, experimental points lay between curves corresponding  from 30 μs to 100 μs witch indicates anisotropy (see figure 4b).

Fig. 4.a) Scheme of sample plugs orientation b) Barre granite dynamic tensile strength dependence on sample orientation.

Summarized results of data interpretation based on incubation time approach represent in Table 1. Anisotropic coefficients obtained for anisotropy estimation (AS – anisotropy tensile strength coefficient, AI anisotropy incubation time coefficient).Individual analysis in planes orthogonal to X-axe, Y-axe and Z-axe demonstrated on figure 5.