Investigating the Effects of Percussion on Excavation Forces

Percussive excavation is researched as a viable technology to reduce the shear strength of the dry lunar soil simulant JSC-1A. Experimental tests were conducted in a percussive and quasi-static test bed, which used a replica Surveyor scoop as the excavation tool. The effects of percussion, relative to measured excavation baseline draft forces, are presented in the context of six different variables. The test variables include percussive frequency, percussive impact energy, excavation speed, excavation depth, angle of attack, and relative soil density. It is concluded that percussion reduces the shear strength of dry JSC-1A by removing the effects of soil dilatancy from the internal friction angle along the shear failure boundary layer.