Fiber- Reinforced Membrane Modeling Based on Constant Edge-Length Constraints

Fiber reinforcement is a well-studied approach for fabricating soft actuators. In this approach, an inextensible fiber is employed to constrain the deformation of a membrane in the fiber axial direction. In this way, the desired deformation can be achieved. In conventional finite element modeling, usually, the fiber and the membrane are modeled separately and then combined into a single model by imposing constraints. However, this is a time-consuming process. We propose a new approach to implicitly model an inextensible fiber by imposing geometric constraints, namely, the constant edge-length constraints. In our approach, the fiber model is integrated into the membrane model as mesh edges, and the two models are combined into one. As a result, the modeling process is simplified. The simulation results show that by employing the proposed model, the deformation behavior of fiber-reinforced soft structures can be simulated.