Description
The fracture toughness apparatus is purpose-built for determining the fracture toughness of rock using chevron notched core specimens in a three-point bend configuration. This property plays a pivotal role in classifying and characterizing rocks based on their resistance to crack propagation. The apparatus comprises several key components, including a 10-KN load frame, a load cell, a 3-point bend fixture, and specialized fracture toughness software. In the testing process, a rock sample prepared with a chevron or V-shaped notch, oriented perpendicular to the core axis, is positioned on two support rollers. A compressive load is applied to separate the sides of the notch, which leads to transverse splitting of the specimen through crack propagation and coalescence in the unnotched part of the cross-section. Throughout the test, the load is accurately measured using a dedicated load cell, while the displacement of the load point and the crack mouth opening displacement (CMOD) are monitored using two LVDT transducers and a clip-on gage, respectively. These measurements are then utilized to determine the fracture toughness of the rock, including both level I and level II fracture toughness values.
Specifications
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Standard | IRSM recommended method |
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Compression load capacity | 10 kN
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Specimen diameter
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up to 54.7 mm and 4 inches
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Specimen length | 16 inches |
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Wetted parts
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Stainless steel
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Benefits
Designed for easy and quick installation
ISRM-compliant device
Designed for testing a range of specimen diameters
Video presentation: