Modeling and Dynamics Analysis on Pseudo-Rigid-Body for the Swing Vibrator of the Caudal-Fin-Like Valve-Less Pump

Abstract

A bio-inspired swing vibrator applied in fluid driving has the characteristics of a large deformation and rigid-lexible structure. Currently, there is a shortage of influential theories and methods to analyze its vibration. This research established a dynamic model for studying the bionic rigid-flexible swing vibrator based on pseudo-rigid-body theory. The weak coupling relationship between vibration arm DOF and flexible caudal-fin DOF was proposed by comparing the diagonal elements with the characteristic matrix's anti-diagonal elements. Analysis results showed that the presence of a flexible caudal-fin had minimal impact on the vibration modes of the vibration arm. The flexible caudal-fin vibration could be treated as a dynamic response that uses the vibration arm's end as a foundation. Experimental studies were conducted, and a laser Doppler vibrometer was used to measure the vibrator's vibration modes. The experimental results indicated that whether the vibrator works in water or in air, the presence of a flexible caudal-fin had little impact on the resonance frequency of the vibration arm. Finally, experimental results were discussed based on theoretical analysis and conclusions. This paper provides an academic tool for modeling, optimization, and a working mechanism analysis on the rigid-flexible swing vibrator.