Dynamic Modelling and Analysis of Flexible Structure Actuated by Dielectric Elastomer

Soft robot is one of the current research hotspots. As the main driving component, flexible joint plays a vital role in the actuating performance of flexible robot, so it is of great significance for the design and development of flexible actuator. Dielectric elastomers (DEs) are suitable for driving joint materials of flexible robots. The design and application of dielectric elastomers actuators (DEA) are the main research contents of this paper. In order to study the driving mechanism of DEA, based on the Absolute Nodal Coordinate Formulation (ANCF) which has a good effect on the description of large deformation of flexible body, this paper uses three-dimensional two-node higher-order beam element to model and simulate the system. By introducing the Neo-Hookean hyperelastic constitutive model and the electromechanical constitutive model of DE material, the internal force and Jacobian of the driven beam and the follower beam are deduced. The dynamic equation of the system is established by using the Newton-Euler equation and solved by the generalized-α method. A DE multilayer structure actuator is designed and applied to flexible gripper mechanism and bionic fish body. In the aspect of statics, the results show that the bending degree of the flexible gripper is positively correlated with the number of actuators and the amplitude of driving voltage. In terms of dynamics, the results show that when the voltage frequency is close to the first-order natural frequency, the fish body can achieve stable swing, and the swing amplitude is positively correlated with the voltage amplitude.