Rock Fracture Toughness Tester

The Rock Fracture Toughness Tester (CT-FTT) loads notched rock specimens to propagate a controlled crack and determine mode I fracture toughness, KIC. It follows the ISRM suggested methods, using chevron bend (CB) and cracked chevron notched Brazilian disc (CCNBD) specimens. Toughness data support hydraulic fracture modeling, rock breakage analysis, and drilling and excavation studies.

How it works

The specimen sits in a fixture matched to the chosen method. For the chevron bend method the core is loaded in bending across the notch. For the CCNBD method a disc with a central chevron notch is loaded across its diameter. As load rises, a crack starts at the chevron tip and grows until the critical load is reached. The tester records the peak load, and fracture toughness is calculated from that load and the specimen geometry.

Applied load is controlled; where configured, crack-mouth opening displacement (CMOD) is controlled as well. Compression load capacity is 100 kN. Listed specimen diameters are up to 54 mm (2.125 in) and 100 mm (4 in), and listed specimen length is 16 in. Wetted parts are high grade stainless steel. Fixtures and specimen geometry are configured per method.

What is included

• Loading unit, 100 kN compression capacity
• Test fixtures for the selected ISRM method

Specify for your project

• Test method: chevron bend, CCNBD or both
• Specimen diameter and length
• Control mode: load, or CMOD where configured
• Rock types and expected peak load within 100 kN
• Data acquisition and reporting: stated in the project datasheet

This description defines the product family. Guaranteed performance, included hardware, exclusions, interfaces and acceptance criteria are stated only in the project-specific technical proposal and approved datasheet.

Features

• Standard: ISRM suggested method
• Compression load capacity: 100 kN
• Specimen diameter: up to 54 mm (2.125 inches) and 100 mm (4 inches)
• Specimen length :16 inches
• Wetted parts: High grade stainless steel

Benefits

• Designed for easy and quick installation
• ISRM-compliant device
• Designed for testing a range of specimen diameters