High-velocity frictional properties of gabbro

摘要: High-velocity friction experiments have been performed on a pair of hollow-cylindrical specimens gabbro initially at room temperature, slip rates from 7.5 mm/s to 1.8 m/s, with total circumferential displacements 125 174 m, and normal stresses 5 MPa, using rotary-shear high-speed testing machine. Steady-state increases slightly increasing rate about 100 (velocity strengthening) it decreases markedly higher velocities weakening). in the velocity weakening regime is lower for non-melting case than frictional melting case, due perhaps severe thermal fracturing. A very large peak always recognized upon initiation visible melting, presumably owing welding fault surfaces solidification melt patches. Frictional properties thus change dramatically displacement high velocities, such non-linear effect must be incorporated into analysis earthquake processes.