On the shock performance of a nonlinear vibration isolator with high-static-low-dynamic-stiffness

Horizontal active vibration isolator (HAVI) using electromagnetic planar actuator (EPA)

“…In addition, stiffness of FBC can be adjusted by compression force and NOMENCLATURE A 1-3 = approximate dimensionless coefficients for horizontal stiffness of FBC c = dimensionless damping coefficient g = dimensionless gravity acceleration F x,y,z , f x,y,z = dimensionless and dimensionless forces of EPA i d,q = direct and quadrature currents of EPA Kf x,y,z = dimensionless horizontal and vertical stiffness of FBC k p , k i , k d = PID gain of controller L a , L b = length of flexible and rigid parts of FBC m = dimensionless mass of isolator n = shape ratio of FBC n b = number of FBCs r a,b = radius of flexible and rigid parts of FBC z g = air gap of EPA δ x,z = small dimensionless horizontal and verital deformation of FBC τ = magnet pitch λ pm = maximum flux linkage ω x,y (t) = dimensionless disturbance SDOF vibration isolators with FBC were studied in high-static and low-dynamic stiffness isolator systems. [11][12][13][14][15] On actuator for horizontal isolators, complex mechanism or large space is necessary since actuator has many limitations such as stroke, degree of freedom and capacity. Although piezoelectric actuators (PZTs) 16 and voice coil motors (VCMs) 17,18 are commonly used as actuators, they have limited stroke and provide SDOF.…”

Periodic solution and bifurcation of a suspension vibration system by incremental harmonic balance and continuation method

“…In the present work, the nonlinear vibration characteristic of a compressed air generator, with the similar negative stiffness of that studied by Tang and Brennan [18], is investigated. The main motivation of this work is to investigate the dynamic behavior of a compressed air generator and to provide a new strategy to reduce the vibration of it in practice.…”

“…The natural frequency of the isolator was validated experimentally, and the effectiveness of the isolator for vibration isolation was tested. Tang and Brennan [18] studied another type of HSLDS isolator, which is comprised by a vertical spring and two horizontal springs. Their work validated the advantage of the HSLDS isolator.…”

Experimental characterisation of dry friction isolators for shock and vibration

“…This model is based on the Duffing oscillator, which has been recently studied in its vibration isolation properties. 16,17 This model is characterized by a cubic elastic force component, which can be hardening or softening. Isolators based on this model exhibit a low dynamic stiffness around a particular equilibrium position, and a high static stiffness otherwise, thus presenting improved isolation properties.…”