Axial-Torsion Test System

The importance of understanding deformation and fatigue of materials (metals, composites, elastomers etc.) under multiaxial loads, resulting from service conditions, has gained significant recognition by the scientific community towards the development of materials for various engineering structures (piping in nuclear power plant, aircraft, civil, mechanical, vehicles, windmills etc.). Torsional testing reproduces pure shear. Characterization of axial-torsion response serves the development of material constitutive relationships and appropriate failure criteria.

Several challenges confront the development of axial torsion testers: These include (a) cross-talk between the axial and torsional channels that affects the quality of both control as well as measurement – axial response affects stiffness in torsion and vice versa, an axial load can distort torsional moment readout and vice versa; (b) specimen alignment to ensure coincidence of axial, torsional and specimen axes; (c) extensometry to handle both axial and torsional displacement on the specimen and (d) specimen fixturing without backlash along either axis.

BISS has developed and supplied axial-torsion test systems (ATTS) worldwide, with rating ranging from 10N to 600kN axial load and 10Nm to 2kNm torsional load with test frequency range up to 50 Hz.


  • Axial capacity up to ±600 kN
  • Torsional capacity up to ±2 kNm
  • Actuator in base or in upper crosshead to suit application
  • Wide range of system options, grips, fixtures and accessories
  • Optional capability for instrumented testing with up to 12 strain gauge channels
  • Electronically servo-controlled variable flow, variable pressure, low noise, energy efficient pump
  • Up to 40 kHz, 32-bit digital closed loop control
  • 32-bit data acquisition
  • User friendly software
  • Provision for user programmability


  • LCF & HCF tests
  • Testing of pressurized metal tubes
  • Low strength component & material testing
  • Biomaterial test applications
  • Fracture mechanics under axial, torsional and axial-torsion loading

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