Performance analysis of the seat suspension using different models of the optimal negative-stiffness-structures

Abstract

Three different models of the steel spring (SS), the roller-spring (RS), and the air spring (AS) in the negative-stiffness-structure (NSS) used for the driver’s seat suspension system are proposed to ameliorate the vehicle’s ride comfort. A vehicle dynamics model with the driver’s seat isolation system added by the SS, RS, and AS is built and simulated under the different operating conditions of the vehicle. The geometric dimensions and the dynamic stiffness coefficients of the SS, RS, and AS in the NSS are optimized by the genetic algorithm to further enhance the vehicle’s ride comfort. The performance of the optimal SS (OSS), the optimal RS (ORS), and the optimal AS (OAS) in the NSS is assessed through the weight Root-Mean-Square value of the deformation of the driver’s seat suspension system (z_wsb) and the driver’s seat acceleration response ( ${\stackrel{··}{z}}_{\mathrm{ws}}$ ). The research shows that with the NSS added into the driver’s seat suspension system, the driver’s ride comfort and the deformation of the driver’s seat suspension system are remarkably improved compared to the driver’s seat suspension system without the NSS. Additionally, the design parameters of the SS, RS, and AS in the NSS also significantly influence their isolation performance. With using the OSS, ORS, and OAS in the NSS, the stable result of the non-dimensional restoring force of the OAS at a variable range of the non-dimensional deformation z is smaller than both the OSS and ORS. Therefore, the OAS better improves the driver’s ride comfort compared to both the OSS and ORS. In particular, the z_wsb and ${\stackrel{··}{z}}_{\mathrm{ws}}$ with the OAS are remarkably decreased by 40.05% and 36.28% compared to the OSS; and by 62.57% and 86.66% in comparison without the NSS, respectively. Therefore, the OAS in the NSS should be applied to the driver’s seat suspension system to further ameliorate the vehicle’s ride quality.