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Multi-Directional Simple Shear (MDSS) Test System

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Multidirectional excitation, chamber pressure control, direct pore pressure measurement with shear and strain controlled testing



The CRT-MDSS is a Multi-Directional Simple Shear (MDSS) Test System (also known as earthquake simulation machine) designed in partnership with Texas A&M University, USA, and Cambridge University, UK. The CRT-MDSS is capable of applying multi-directional loading to hydraulically saturated soils, clays and other unbound materials under confined conditions simulating those found in-situ.

Controlled using the state of the art cDAC data acquisition and control system alongside our flagship Dimension software, with 3 independent loading axes and a confining pressure system the CRT-MDSS combines ultimate flexibility with complete ease of use for this most demanding area of materials testing.

The CRT-MDSS is designed primarily to test cylindrical samples of up to 100mm diameter but specimens of up to 150mm diameter can be tested with special endcaps. A hydraulic vertical actuator coupled with a hydraulic horizontal x-y table, provide the loading for the specimen. LVDTs provide position feedback, and load cells provide load feedback on all three axes allowing the system to be used in both position and load control or any combination of these. During testing a 6 axis (3 Force, 3 Torque) load cell which is installed directly above the specimen is used to measure the loading experienced by the specimen.

Samples can be tested dry or saturated and subjected to monotonic, unidirectional cyclic, and multidirectional loading. The Dimension software is easily configured to enable the MDSS to perform complex loading paths, such as figure-eight, circular and user defined patterns to a cylindrical specimen over a large range of shear stresses.

The CRT-MDSS Multi-Directional Simple Shear Test System incorporates a large pressure cell which is used to apply confining pressure to membrane encapsulated specimen. Water lines are included and connect directly to the specimen endcaps to allow the specimen to be saturated. A backpressure control system is used to control the pressure in the water lines. Excess pore pressure is also measured to allow the shearing phase of testing to be monitored, which enables, specimens to be subjected to conditions that closely simulate real world situations.

Key Features

  • Vertical actuator with integral stroke LVDT and Interface Force Universal Load Cell
  • Precision X-Y table manufactured to the highest quality to ensure axes are truly independent, incorporating integral stroke LVDTs and Strainsert Universal Load Cells
  • Large diameter steel construction pressure cell with SMC pressure controller and pressure transducer for application of confining pressures to the test specimen with hydraulic raise and lower for easy and unrestricted access to the test area
  • Parker Hannifin DF-Plus proportional control valves on all axes for unrivalled reliability and excellent control
  • State of the art cDAC digital data acquisition and control unit with 2 servo cards (4 control axes) and 1 acquisition card (8 channels of data acquisition) as standard (additional axes/channels available on request)
  • Optional back pressure system comprising SMC back pressure control system and differential pressure measurement (requires additional servo card (2 control axes) and acquisition card (8 channels))
  • Optional 6-axis Force-Torque cell (requires additional acquisition card (8 channels))


Hydraulic Power Unit comprising:

  • Oil reservoir
  • Inverter controlled variable flow rate for maximum efficiency
  • User settable system pressure via pushbutton controller
  • Fixed displacement pump
  • Hydraulic Power Unit enclosure with noise reduction technology


Key Uses

  • Earthquake simulation
  • Soils, clays, and other unbound materials
  • Geological testing
  • Hydraulic saturation


cDAC – DATA ACQUISITION AND CONTROL SYSTEM

cDAC, our next generation class leading digital controller is unparalleled in its fi eld. We combine cDAC, our flagship universal test software DIMENSION to provide you with the ease of use and flexibility required for testing without limit for the next 20 years and beyond.

  • 24 bit resolution, 5kHz per channel
  • Up to 32 TEDS enabled acquisition channels accept any transducer type
  • Up to 8 servo axes, each capable of up to 1024 set points per cycle
  • Up to 16 digital input & output channels
  • Ethernet/USB/RS232 to PC communication


DIMENSION – SOFTWARE

  • User friendly, intuitive and reliable Windows software developed using LabVIEW
  • Create your own or select from the range of pre-installed test routines
  • See real-time data and the sequence of events as they happen
  • Start, stop and skip stages of the program as you want, reconfi gure in realtime
  • Create charts, graphs and reports to analyse and document the application
  • Build a database of all the hardware either real or calculated, to monitor and edit as you want
  • Setup and modify the cDAC modules and their I/O to fi ne tune the process

Accessories

Accessories are not included in the price of main device (unless stated otherwise) and may be purchased separately if required.


CRT-MDSS-MEM100 Wire wrapped 100 mm membranes for specimen confinement/saturation
CRT-MDSS-MEM150 Wire wrapped 150 mm membranes for specimen confinement/saturation
CRT-MDSS-LOAD-X Additional X Load Cell
CRT-MDSS-LOAD-Y Additional Y Load Cell
CRT-MDSS-LOAD-Z Additional Z Load Cell
CRT-MDSS-END100 100 mm end caps
CRT-MDSS-END150 150 mm end caps

Specifications

Technical specifications are subject to change without notice.


Z-Axis

Actuator Force klbf 2.5
Actuator Stroke mm 100
Load Cell Capacity klbf 2.5 (others available on request)
Actuator Position Transducer Range mm 0 to 100


X-Y Table

Actuator Force klbf 250
Actuator Stroke mm 20
Load Cell Capacity klbf 250 (others available on request)
Actuator Position Transducer Range mm -10 to 10


Pressure Range bar 0 to 5
Diameter mm 470
Differential Pressure Measurement Range bar 0 to 5
Machine 230 VAC, single phase, 13 Amps
Power Pack 230 VAC, single phase, 13 Amps or 415 VAC, 3 phase, 16 Amps
Dimension mm (W x D x H) TBC
Weight (approx.) Kg TBC
PC Not Included