Rock Fracture Toughness Tester

Fracture parameter determination: Quantify the critical stress intensity factors (\ (K_ {IC} \), \ (K_ {IIC} \)) and fracture energy of rocks.

Engineering safety assessment: Predicting the crack propagation behavior of rock mass under load (such as hydraulic fracturing, slope instability).

-Research and teaching: Study the mechanism of rock fracture and the influence of microstructure.

1. The three-point bending method is used to determine the fracture toughness of rocks using cylindrical specimens with straight incisions, which is suitable for hard rocks.
2. Sample size: diameter of 48mm to 54mm, length greater than diameter ratio of 3.5 to 4 times.
3. The ratio of the distance between the two support points to the diameter is 3.33.
4. The ratio of depth to diameter of the straight incision is 0.35-0.50, and the incision width is not greater than 1.5mm
5. Load: 0-200kN ± 5N
6. Three point bending test fixture: center position of upper support point; Bottom pivot spacing 200mm (applicable for 50 × 50 × 200mm)
7. Loading rate: 3N~5KN/s
8. Loading speed: 0.001-10mm/min
9. Displacement rate: 6 × 10-4mm/s.
10. Travel range: 0-10mm ± 0.001mm
11. Clamp type extensometer: gauge length 3.0 mm; Measurement range+2.5 mm/-1.0 mm (optional)
12. Real time LCD display, vertical load. Standard industrial computer software is used to process and collect force, deformation cracks, expansion deformation, raw data, graphical curves - deformation curves, and rock crack expansion deformation curves.