SHIVA is capable of shearing ring-shaped samples at sliding velocities up to 9 m/s, accelerations of 40 m/s2 and normal stresses up to 50 MPa. In comparison with existing high speed friction machines, this apparatus extends the range of sliding velocities, normal stresses, sample size and, more importantly, accelerations.
INGV performs experiments on rock samples of a variety of compositions using slip velocities and accelerations that simulate slip velocities function that occur during earthquakes.
In addition, TEES srl develop a pore fluid system and a pressure vessel in order to perform experiments that include the physical-chemical processes that occur during slow interseismic periods.
With this apparatus INGV is able to simulate the transient load variation expected during seismic failure on natural faults and measure the related dynamic weakening, frictional evolution and slip velocity on the sample.
The characterization of the rock frictional behaviour under combined conditions of low to high slip velocity and extreme and rapidly variable loan, is expected to provide important insights into the mechanics of earthquakes.
Air-actuated hydraulic piston: maximum pressure of 6 bar or 18 kN
Arm increases thrust to 50 kN or 70 MPa
Loadcell (full scale 50 kN, resolution 2.5 N)
measures normal load up to 70 MPa with 0.035 MPa resolution
Brushless engine: peak power 270 kW.
Rotation speed up to 3820 RPM.
Small engine: nominal power 5.15 kW.
Rotation speed up to 5790 RPM
Minimum sliding velocity of 1 μm/s