Modeling of the Burrowing Mechanism by Razor Clam: Role of Penetration Kinematics

It has been reported that the Atlantic razor clam can burrow with an extremely high efficiency due to its well-evolved dynamic penetration kinematics. In general, the periodic penetration process is essentially an issue involving dynamic interaction between a shape-changing penetrator and the soil particles. In this paper, the three-dimensional discrete element method (DEM) modeling method was used to preliminarily study the influence zone created by body expansion. The real penetrator was simplified as a two-body structure: a conical foot and a cylindrical body with a time-varying radius. To mathematically visualize the influence zone at different expansion conditions, distributions of average normal contact force and particle displacement across the sample are investigated. Results show that the expansion ratio and expanding rate have significant impact on the influence zone. Furthermore, a low lateral resisting force and large influence zone can be achieved by using a low expansion ratio and expansion coefficient.