9622431 Prakash A study will be made of the high speed shear deformation of surfaces under varying normal pressures and at various temperatures. From the shear deformation behavior the frictional forces will be determined and it is intended to eventually build a constitutive model for interfacial friction. Two different experiments will be performed to obtain complementary data. One uses a conventional split Hopkinson bar to simulate rubbing of surfaces in contact under varying normal stress. The other uses a modified high speed impact apparatus where two parallel plates are impacted at high speed. By varying the speed of impact and the inclination of the plates, both normal forces and surface traction forces can be varied. Tangential displacements are measured optically and are used to with one-dimensional wave theory to derive variations of shear stress and slip velocity with time. ***
