GDS True Triaxial Apparatus

Product Code : GDSTTA

The GDS True Triaxial Apparatus (GDSTTA) has the defining characteristic that, unlike conventional triaxial apparatus, all three principal stresses can be controlled independently, rather than just two in a conventional triaxial system. This allows a wider range of complex stress paths to be performed. This dynamic cyclic system is powered by advanced electro-mechanical actuators or optional hydraulic actuators and is an extremely sophisticated research tool.

Vertical and one horizontal axis are loaded via the dynamic actuators (axis 1 and 2), stress control is provided for the 2nd horizontal axis, (axis 3) via cell pressure.

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Key features Benefits to the user
Stress or strain is applied to a 75mm x 75mm x 150mm sample independently on three axes: Two pairs of matched dynamic rams for axes 1 and 2, and a confining fluid provides pressure for the 3rd axis on load readings.
Ram specification: Each ram has its own internal submersible load cell and displacement transducer to ensure friction effects are minimised.
Electro-mechanical actuators as standard: Electro-mechanical actuators provide an easier to use and environmentally friendly solution for accurate testing to 5Hz. Electro-mechanical actuators do not require a hydraulic power pack to be present, hence no requirement to service a powerpack or to protect system users from noise generated by a powerpack.
Custom designed optional hydraulic actuators: The hydraulic actuators have been custom designed by GDS to be seal-less with hydrostatic bearings. This improves the actuator performance (up to 10Hz) and reduces whole-life servicing costs as there are no piston seals to replace. Each actuator pair can be controlled in “static-mode” with either constant, ramp or slow cyclic targets in terms of load, stress or displacement. 
Sample preparation: Full sample preparation equipment for cohesive and non-cohesive samples is provided with the system including a specially designed soil lathe for producing cuboidal samples.
Actuators

4

Axial Force Accuracy

0.1% FRO

Axial Force Accuracy

Dependent on range

Computer Interface

USB

Dimensions

2250mm tall, 1750mm wide, 550mm deep

Displacement Accuracy

0.1% FRO

Displacement Range

50mm per actuator (100mm per axis)

Displacement Resolution

<0.0001mm

Load Range (kN)

5kN/10kN/20kN Electro-mechanical or 28kN Hydraulic.

Operating Frequency (Hz)

0 to 5

Power

3 phase

Pressure Accuracy

Dependent on chosen pressure controller

Pressure Range (MPa)

2

Sample Sizes

Max 75 x 75 x 150mm (alternatives on request)