Research on Displacement Transfer Characteristics of a New Vibration-Isolating Platform Based on Parallel Mechanism

Abstract

Based on the parallel mechanism theory, a new vibration-isolating platform is designed and its kinetic equation is deduced. Taylor expansion is used to approximately replace the elastic restoring force expression of vibration-isolating platform, and the error analysis is carried out. The dynamic-displacement equation of the vibration-isolating platform is studied by using the Duffing equation with only the nonlinear term. The dynamic characteristics of the vibration-isolating platform are studied, including amplitude-frequency response, jumping-up and jumping-down frequency, and displacement transfer rate under base excitation. The results show that the lower the excitation amplitude, the lower the initial vibration isolation frequency of the system. The influence of the platform damping ratio on displacement transfer rate is directly related to the jumping-down frequency Ω and the external excitation frequency. The vibration-isolating platform is ideally suited for high-frequency and small-amplitude vibrations.

Improvement of vibration isolation performance of QZS platform in chaotic interval based on damping increase control method

“…The new QZS isolation vibration platform, designed by our research team, is mainly composed of upper and lower springs, which provide negative and positive stiffness respectively. The vibration isolation platform is able to possess quasi-zero stiffness near the static equilibrium position by reasonable arrangement of the position of springs and appropriate matching of the system parameters [14]. At the same time, the flexible adjustment of stiffness and damping of the vibration isolation platform enables it to regain quasi-zero stiffness near the static equilibrium position by adjusting the stiffness and damping coefficients when the mass of the isolated object is changed, to improve the versatility of the vibration isolation platform.…”

“…The vibration isolation platform has the excellent characteristics of "high static low dynamic", which resolve the contradiction between low frequency vibration isolation and load capacity. The parameter matching and displacement transfer characteristics of the vibration isolation platform have been carried out in the early stage [2,14]. Starting from the chaotic motion of the nonlinear vibration isolation system, this paper proposes a damping increase control method to improve the vibration isolation performance of the vibration isolation platform in the chaotic interval.…”

Design and simulation of shear-tension spring-type quasi-zero stiffness isolator

“…In recent years, many scholars and experts at home and abroad have conducted in-depth investigations into the principles, applications, and expansion of the quasi-zero stiffness system [1][2][3][4]. Literature [5] studies a quasi-zero stiffness vibration isolation system consisting of a pair of inclined springs and a vertical spring, and analyzes static stability of the quasi-zero stiffness isolator. Literature [6] designs an adjustable quasi-zero stiffness isolator, and estimates the relationship between the system parameters.…”