Modelling of Innovative Controllable Structures Made of Granular Materials

Abstract

Abstract. The viscoplastic behavior of "innovative" structure is considered. Investigated structures are created on the basis of vacuum packed particles. Partial vacuum generated inside a hermetic sleeve filled with loose granular material transforms the system from semi-liquid to semisolid state. Such phenomenon, known as a "jamming mechanism", is strongly nonlinear in considered structures. Special granular structures have recently found interesting engineering and biomedical applications such as vacuum mattresses, orthopedic orthesis, universal robotic grippers and flexible endoscopes. To capture a response of the specially designed granular sample to external loading, a Bodner-Partom viscoplastic constitutive model has been chosen. The identification procedure is based on experimental compression tests realized at various strain rates and underpressure levels.