Effect of snakeskin-inspired patterns on the shear response of soil - continuum interfaces

ABSTRACT The interface shear responses of soils and 3D printed continuum surfaces with patterns inspired by three distinctive snake-scale morphologies are studied. Interface shear tests are conducted under low normal stresses in cranial (where soil shears against the scales) and caudal (where soil shears along with the scales) directions. The experiments show that the snakeskin-inspired surfaces with different heights and shapes of the scales exhibit different shear responses and mobilize frictional anisotropy (difference in peak interface friction angles) in the range of 3–9 degrees. In the cranial direction, all the snakeskin-inspired patterns mobilize the peak internal friction angle of the neighbouring soil at the interface after a critical normalized roughness of the surfaces. Further, the snakeskin-inspired patterns exhibit significant strain-softening behaviour in comparison to an unpatterned surface. Rounded soil particles exhibit a lower frictional resistance and stick-slip phenomenon in the post-peak interface shear response, unlike angular soil particles.