Design of cab seat suspension system for construction machinery based on negative stiffness structure

Xin Liao,Xiaofei Du,Shaohua Li

doi:10.1177/16878140211044931

Abstract

In order to improve the vibration isolation performance of cab seat and ride comfort of the driver, a seat suspension structure of construction machinery cab is proposed based on negative stiffness structure (NSS) in this paper. The influences of different parameters of suspension system on dynamic stiffness are analyzed. The configuration parameter range of suspension system is obtained. Then, the nonlinear dynamic equation of the seat suspension system is established and the NSS optimization model is proposed. The vibration transmissibility characteristics of suspension structure are analyzed by different methods. The results show that the displacement and acceleration amplitude of optimized seat suspension system are obviously reduced, and the VDV and RMS in the vertical vibration direction for the seat are respectively decreased by 87% and 86%. The vibration transmissibility rate SEAT and the Ttrans are both decreased. Moreover, the peak frequencies of the vibration transmitted to the driver are not near the key frequency values which are easy to cause human discomfort. It indicates that the design of seat suspension system has no effect on the health condition of the driver after being vibrated. The advantages of vibration isolation performance of the designed NSS suspension system are demonstrated, improving the driver’s ride comfort and the working environment.

Highlights

In nearly 20 years, more and more attention has been paid to the ride comfort and humanized design of vehicle seats with the continuous improvement of road traffic
It illustrates that the vibration isolation performance of the seat suspension system is better
Even if there is uncertainty of distance ratio and change of load mass, the results shows that the designed negative stiffness structure (NSS) suspension system for construction machine has better vibration isolation performance and the change in the vibration transmissibility can be achieved by the adjust of distance ratio of additional inerter elements especially when construction machine is in poor working conditions

Summary

Introduction

In nearly 20 years, more and more attention has been paid to the ride comfort and humanized design of vehicle seats with the continuous improvement of road traffic. According to the principle of virtual work, the restoring force F of the system in the vertical direction is obtained suspension system will be affected by different parameters, such as spring stiffness, damping coefficient, length of connecting rod, and so on. It can be found that the dimensionless force F0 of the system will peak in a short time when the value of g1 is especially small This situation should be avoided to occur when designing parameters so as not to affect the dynamic characteristics of the suspension system. When the value of g2 is less than 1, the initial value of the dimensionless force F0 begins to change irregularly, and the value of F0 decreases with the increase of displacement In this case, the stiffness of the suspension system is negative stiffness, it is not suitable for the design of the above negative stiffness model structure. The value is selected to be a little larger, and in order to reduce the displacement deviation caused by the input of different mass of the system, the stiffness of the support spring is increased moderately

Evaluation criteria for suspension systems

Results

Conclusion