Performance enhancement of vehicle suspension system with geometrically nonlinear inerters

This research investigates the nonlinear dynamics and performance enhancement of a suspension system using a diamond-shaped linkage with inerter (D-inerter). The proposed suspension system consists of two inerters embedded in a four-bar linkage mechanism connected with a spring and a damper. Both sinusoidal and random road profiles are considered as external excitation sources. The evaluation of vibration isolation and riding comfort performance is based on displacement transmissibility, acceleration amplitude, car body acceleration, suspension stroke, and dynamic tyre load. The results show that compared with a linear suspension system, the D-inerter has a broader bandwidth of enhanced isolation and lower resonant peak. It is found that a larger inertance value and initial length between the ends of inerter can effectively improve the suppression performance of the nonlinear suspension. The root mean square of vehicle body acceleration with the D-inerter is decreased by 21.5% at the speed of 30 m/s. Additionally, design guidance is provided to select optimal inertance values for improved suspension performance. The results demonstrate that the D-inerter is beneficial for enhancing the suspension structural stability, riding comfort, and vibration suppression, which can potentially be employed for vibration isolation in suspension systems.