Vibration isolation using a bar and an Euler beam as negative stiffness for vehicle seat comfort

Abstract

In this article, the behavior and the efficiency of a nonlinear passive vibration isolator based on a bar and an Euler beam are investigated analytically. The proposed isolator is specifically for isolating vehicle seat from unwanted disturbances in the low frequency range, thereby making the seat comfortable for the driver. The static characteristics of the negative stiffness as well as the nonlinear mathematical model are presented, and its dynamic characteristics are investigated using the harmonic balance method. In addition, the effect of the initial geometric imperfection of the Euler beam is included in the study. The study shows that the performance of the negative isolator has a large isolation frequency range than that of the linear isolator. The configuration parameter choice for the seat base will be vital for the suitable application of this isolator.

An asymmetric quasi-zero stiffness vibration isolator with long stroke and large bearing capacity

“…The fifth order Taylor series expansion of Eq. ( 19) are shown as 𝐹 ̃𝑞 = 𝜑 0 + 𝜑 1 (𝑢 ̃− 𝑢 ̃0) + 𝜑 2 (𝑢 ̃− 𝑢 ̃0) 2 + 𝜑 3 (𝑢 ̃− 𝑢 ̃0) 3 + 𝜑 4 (𝑢 ̃− 𝑢 ̃0) 4 + 𝜑 5 (𝑢 ̃− 𝑢 ̃0) 5 + 𝑜(𝑢 ̃)…”

“…Installment of vibration isolators between vibration source and isolated objects is a common way for vibration isolation and has been widely used to maintain the reliable operation of precision instruments [1,2], improve the comfort of vehicle ride [3][4][5], assist space launch or on-orbit operation [6], ensure the safety of building constructions or bridge structures [7,8] and so on. With the development of vibration isolation technology, diverse vibration isolators have emerged to cope with the ever increasing demands for high vibration isolation performance, especially the demands for low frequency and even ultra-low frequency vibration isolation [9,10].…”

“…The common way to construct the passive QZS-VI is parallel connecting negative stiffness element (NSE) with positive stiffness mechanism. According to the composition and structures of NSEs (e.g., oblique spring, horizontal spring, cam-roller-spring, magnetic spring, Euler buckled beam), diverse types of passive QZS-VIs can be constructed [3,5,[12][13][14][15][16][17][18][19][20][21][22]. Waters and his co-workers [12,13] studied the static and dynamic characteristic of QZS-VI with two oblique springs served as NSE.…”

Magnetic ring array with high-amplitude negative stiffness for high performance micro-vibration isolation

“…Inspired by inclined springs, cam-roller-springs with piecewise linear-nonlinear stiffness were established and modified for allowing different loads and isolating torsion-translational vibrations (Ye et al, 2020; Zhang et al, 2020). Euler buckled beams under large deformation (Oyelade, 2019), scissor-like structures (Guo et al, 2020; Zou et al, 2021), diamond-shaped structures (Wang et al, 2021a) and biro-structures (Sun et al, 2021) were also adopted in low-frequency vibration isolation systems to generate nonlinear negative stiffness. In addition to the vertical monolayer and single degree of freedom mentioned above, vibration isolations for in-plane (Liu et al, 2021d), multi-layer (Wu and Tang, 2021) and multi-degree of freedom (Leandri et al, 2021) can also be accomplished by connecting positive and NSSs in parallel.…”

Design and experimental validation of a vibration isolator with high-static low-dynamic stiffness and operating point variable property

“…By combining elastic springs, in particular geometries and tunable geometric nonlinear stiffness, HSLDS isolation mounts were investigated (Friswell and Saavedra Flores, 2013). An isolator with HSLDS property based on bar and Euler beam was investigated by Oyelade (Oyelade, 2019). Similarly, scissor-like structures (Sun and Jing, 2015), pre-compressed cam-roller mechanism (Zhou et al, 2015a), knife edge-supported sliding beam (Huang et al, 2014), and parabolic-cam-roller mechanism (Sun et al, 2019a(Sun et al, , 2019b were also utilized to obtain the HSLSD characteristic.…”