MAST 6DOF Laboratory Six Degree of Freedom Crosshead Actuator

Versatile large-scale structure testing apparatus

  • Ability to conduct multi-axial quasi-static cyclic testing, quasi-static pseudo-dynamic testing, and continuous pseudo-dynamic testing on large-scale structural subassemblages including portions of beam-column frame systems, walls, bridge piers, abutments, towers, and other structures.
  • Accommodates test specimens up to approximately 20 ft. (6.1 m) long and 28.75 ft. (8.7 m) high. Longer test specimens may be managed by placement along the diagonal.
  • Displacements of up to ± 20 inches (± 508 mm) and loads up to ± 1,320 kips (± 5,900 kN) can be achieved in the vertical direction.
  • Displacements of up to ± 16 inches (± 406 mm) and loads up to ± 888 kips (± 3,900 kN) can be achieved in each of the two horizontal directions.

Sophisticated control with ease of use

  • Advanced six-degrees-of-freedom (6-DOF) servo-hydraulic control system, designed by MTS Control Systems, allows researchers to control the crosshead and specify the three translational and three rotational DOFs in either displacement or mixed-mode control. DOFs may be constrained by a master-slave relation to be a linear combination of the values of other DOFs.
  • Customized hydraulic control software is powerful yet simple to use, providing a comprehensive interface for researchers to interact with the MAST hardware controller.
  • Integrated Quasi-Static Hybrid Simulation using the OpenFresco open-source framework.

Crosshead loading element

  • The 6-DOF forces are transferred through the rigid steel crosshead (94,000 pounds) to the specimen, which is bolted to the underside of the crosshead and the strong floor. The actuators move the crosshead to apply desired loads and deformations.
  • Strategically positioned mounting holes at the bottom of the crosshead allow maximum flexibility for attaching test structures.

Actuator system

  • Four ± 330 kip vertical actuators connect the crosshead and the strong floor and have a stroke of ± 20 inches (± 508 mm). Vertical spacers can be used to vary the height of the crosshead.
  • Four ± 440 kip horizontal actuators connect the crosshead and the L-shaped strong wall, with one pair in the lateral Y direction and one pair in the longitudinal X direction. Each pair provide lateral loads up to ± 880 kips in the orthogonal directions with strokes of ± 16 in (± 406 mm).
  • Four ± 220 kip (± 975 kN) ancillary actuators with a displacement range of ± 10 inches (± 254 mm) permit displacements or loads at other locations on the test specimen.
  • Highly configurable specimen connection system.

MAST Reaction System

  • L-shaped strong walls each seven feet thick and designed to accommodate a wide range of specimen support equipment.
  • Strong floor that is 7.5 feet thick with a 5.5-inch thick steel connection system designed to accommodate a wide range of test structures and loadings.
  • Prefabricated steel grid permitting precise placement of the holes used to tie down specimens.