figure_A07.eps from Forward and inverse problems in the mechanics of soft filaments

Soft slender structures are ubiquitous in natural and artificial systems, in active and passive settings and across scales, from polymers and flagella to snakes or space tethers. Here, we demonstrate the use of a simple and practical numerical implementation based on the Cosserat rod model to simulate the dynamics of filaments that can bend, twist, stretch and shear, while interacting with complex environments via muscular activity, surface contact, friction and hydrodynamics. We validate our simulations by solving a number of forward problems of passive filament mechanics, by comparing with known analytic results and experimental observations relative to solenoid and plectoneme formation in twisted, stretched filaments. We then study active filaments such as snakes and other slender organisms, by solving inverse problems to identify optimal gaits for limbless locomotion on solid surfaces and in bulk liquids.