The TRUTEST system is specifically designed for the mechanical characterization of large cubic rock specimens under fully independent stress control along the three orthogonal principal axes (σx, σy, σz). It enables rigorous reproduction of complex anisotropic in-situ stress conditions and precise simulation of true triaxial loading paths. The system allows high-resolution determination of principal stresses, directional strain responses, and failure criteria under polyaxial loading. The specimen is confined between six servo-controlled hydraulic actuators, configured in opposing pairs along each axis. Each actuator pair applies axial loading to the specimen, ensuring uniform stress distribution across the specimen faces . Actuation is driven by three independent high-pressure syringe pumps, providing closed-loop pressure regulation and fine stress-path control. Axial deformations are continuously monitored using six high-precision LVDT displacement transducers, with two sensors per axis to ensure redundancy and measurement accuracy. Optional thermal control enables subsurface temperature simulation. Ultrasonic monitoring of P- and S-waves allows real-time assessment of elastic evolution and damage. The system also supports true triaxial hydraulic fracturing and wellbore stability evaluation, with real-time acoustic emission monitoring of fracture initiation and propagation.
Download True triaxial cell brochure.pdf
Specifications
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Specimen dimensions |
Type 1:100 x 100 x100 mm Type 2: 200 x 200 x 200 mm Type 3: 300 x 300 x 300 mm |
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Maximum X stress
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100 MPa
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Maximum Y stress | 100 MPa |
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Maximum Z stress | 100 Mpa |
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Temperature range | Ambient to 150°C (optional)
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Wetted part material
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Stainless steel
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Power supply
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220 V 2 Phases, 50/60 Hz
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Benefits
Realistic simulation of in-situ anisotropic stress conditions
Independent control of three principal stresses (X, Y, Z)
High stress capacity for testing strong rock materials
Advanced monitoring capabilities (strain, ultrasonic waves, acoustic emission)
Capability to perform hydraulic fracturing tests under controlled true triaxial stress conditions