Griggs cube, Solid medium apparatus (modified by Gene Robertson)

Multi Anvil

Texas A&M Handin lab 358

Griggs Cube

Griggs, solid-pressure-medium, multiple anvil "cubic" apparatus capable of applying high isostatic stresses or conventional and true triaxial stress states by way of six pistons that load a cubic solid-medium sample assembly, and capable of applying differential stresses on samples, ~1 mm diameter by 2 mm length (normally along a load column of WC, Al2O3 or other ceramic pistons). This apparatus is capable of confining pressures up to 7 GPa and temperatures up to 1200 °C, and measurement of ultrasonic P and S wave velocities in three principal stress directions using external piezoelectric transducers. Absent determinations of internal stresses by distortion of X-ray diffraction at a synchrotron beamline, stresses are only estimated from external load measurements, so this apparatus is used primarily for graduate teaching purposes.

Loading; Unloading; Heating; High Temperature; Ultra-High Temperature; High Pressure; Ultra-High Pressure; Elastic Moduli; Yield Strength; Failure Strength; Strength; Triaxial Stress/Strain