Fully-coupled model of a solid-liquid composite beam*

Elastic structures containing embedded fluid-filled cavities have been receiving considerable attention in recent years in various fields such as smart materials, sensors, actuators and soft-robotics. Such structures can be viewed as meta materials, or solid-liquid composites. Deformation of solid-liquid composites both creates, and is induced by, a fluidic pressure gradient and viscous flow which deforms the cavities and thus the surrounding solid. We examine a beam-like appendage embedded with a set of a fluid-filled bladders, interconnected via elastic slender channels; a common arrangement of the abovementioned fields. Utilizing homogenization and Cosserat models, we model two-way transient interaction, enabling the analysis of highly coupled nonlinear problems with large deformations, extending the scope of existing research. We then show how the obtained coupled equation system enables exploration of new ideas involving soft smart-materials for control of structural response to external excitations as well as energy harvesting applications.