Damon Nguyen

Inspiration is taken from the ventral scales of snake’s underbellies to create soil-structure interface surfaces capable of mobilizing directionally dependent strengths. Interface shear tests are simulated with discrete element modeling (DEM) to investigate the performance of these surfaces and the micro-scale mechanics underlying their behavior. Extra focus is given on the roles attributed to asperity geometry and the distribution of force components along asperity faces.

Surfaces capable of mobilizing directionally dependent strengths can be of benefit to several geotechnical technologies, such as soil anchors and deep foundations. Surface geometries that take inspiration from the ventral scales of snakes can mobilize directionally dependent interface shear strengths. For these systems, shear resistance is comparatively high during cranial shear (against asperities) and low during caudal shear (along asperities). Discrete Element Modeling (DEM) is used to explore the micro-scale mechanics driving this behavior. In cranial shear, large passive forces develop ahead of asperities, significantly increasing shear resistance. In caudal shear, shear resistance arises instead from weaker normal and sliding force components acting over asperities. The combined resistance increases with greater asperity height and shorter asperity length, resulting in a strong negative correlation between shear strength and the asperity ratio, defined as L/H.