Nonlinear Dynamics and Stability of Electromechanically Loaded PVC Gel Cylindrical Tube Actuators

Polyvinyl chloride (PVC) gel is a typical electroactive polymer with significant research value for applications in soft actuators and artificial muscles. Based on the Gent hyperelastic material model, this study establishes a nonlinear dynamic equation for the cylindrical tube structure of PVC gel. On this basis, the influence of key electromechanical parameters, including axial prestretch ratio, pressure, and thickness, on the complex nonlinear dynamic behaviors of PVC gel actuators with cylindrical tube structures is analyzed. These behaviors encompass vibration attenuation, periodic motion, and chaotic responses. Furthermore, dynamic analysis methods such as phase trajectories, Poincaré sections, bifurcation characteristics, and Lyapunov exponent analysis are employed to investigate the nonlinear characteristics of the structure under various loading conditions, covering aspects of stability, periodicity, and harmonic resonance. The operational parameter ranges corresponding to the stable and chaotic states of the structure are identified, and the evolution of chaos within the PVC gel cylindrical tube structure is examined. This work provides control strategies and a theoretical foundation for the further application and development of such structures.