Rock mechanical testing - Equipment

Testing machine for compression tests

Max axial force ca 1,5 MN

Pressure cell

• cell pressure up to 100 MPa
• pore pressure up to 100 MPa

• possible to measure water flow

Equipment for axial and radial deformation measurement

Load measured by load cells (measurement inside the pressure cell is possible)

Control unit

• fast system
• Bumpless "on-the–fly" transfer between various control modes
• Many analogue/digital input/output channels
• Many signal conditioning cards for AC/DC/SG-signals
• Calibration of non-linear sensor signals possible
• Possible to have flexible and advanced control beyond the ordinary
• PID-parameters
• Definition of new signals as function relations of several sensors (e g average of signals from several sensors)
• Separate unit that communicate with an external computer where program commands to the control unit are given. This yields a robust system design.

Flexible setup of test programs for various tests

Control of several parallel processes (e g load, cell pressure, pore pressur, etc)

Specially designed to e g suit uniaxial compression tests including post-failure on brittle materias. This means 

• High stiffness in the entire load chain (load frame, load cell, piston, etc)
• Fast respons (fast servo hydraulics, faast control system)

Equipment for normal and shear loading tests

Normal loading

• max 300 kN compression

• indirect and direct normal deformation measurements

Direct shear tests

• max shear load +/- 300 kN
• shear deformation measurement
• combined normal and shear load
•  active control of normal force during shearing, e g
  - constant normal load (CNL) 
  - constant normal stiffness (CNS), where the normal load is a function of the normal deformation
  - area correction due to shear deformation at normal stress calculation in real time

Connecting othe types of sensors possible, e g AE, strain gauges

Control unit

• fast system
• bumpless "on-the-fly" transfer between various control modes
• many analogue/digital input/output channels
• signal conditioning cards for AC/DC/SG-signals
• calibration of on-linear sensor signals possible
  
• possible to have flexible and advanced control beyond the ordinary
     PID-parameters
• definition of new signals as function relations of several sensors
      (e g average of signals from several sensors)
• separate unit that communicate with an external computer where
     program commands to the control unit are given. This yields a robust
     system design.

Flexible setup of test programs for various tests

Control of several parallel processes (e g normal loading and shear loading)