Dynamic Characteristics and Optimization of Segmented Fork Arm Seat System

Abstract

To improve the low-frequency vibration isolation performance and driving comfort of the engineering seat system, a segmented fork arm seat system is proposed. Firstly, the equivalent model of the n-level segmented seat system is established, the amplitude-frequency response function and phase-frequency response function of the segmented seat system are solved and analyzed. The theoretical study shows that, with the increase of segment levels, the response time of the seat system is shortened, and the attenuation rate of response amplitude is accelerated; with the increase of segment levels, the resonance peak value of the seat system tends to shift continuously, and the low-frequency vibration isolation range expands. Secondly, according to the actual application condition of a loader, the engineering structure of the 3-level segmented fork arm seat system was built, and the structure-stiffness parameters of the segmented fork arm seat system were optimized by multi-objective genetic algorithm. The optimization results show that the 3-level segmented fork arm seat system has obvious vibration reduction effect on the sensitive frequency band of the human body. The vibration reduction effect on road excitation increases by 63.2% on average under driving conditions, 75.8% on uneven road surface, and 65.2% under operating conditions, and the subjective comfort evaluation index of human body increases by two levels.