Seat/Floor Coupling CAE Study for Body/Vehicle NVH

In today's competitive automobile environment with shorter vehicle development time and fewer prototypes/tests, CAE is becoming very crucial for vehicle development. Seat is a critical system of automobiles for customer satisfaction because seat provides support, safety, and comfort especially NVH for vehicle occupants. In this paper, the effects of seat system on body and vehicle NVH were studied. How the seat system affected body and vehicle NVH, and how seat to floor coupling affected vehicle NVH were investigated. Two groups of finite element body models, body-on-frame and unitized body, were used for this study to ensure the effect of body architecture was included in this study. In the baseline body models, the seats were represented by detailed finite element models. Then, several versions of body models were built by modeling seats in different finite element representations. Three critical vehicle road load cases (engine idle, coarse road at 30mph, and rough road at 40mph) were investigated in this study. Body NVH performance (local/global modes and seat track/floor attachment responses) and vehicle road NVH performance (front/rear interior sound and seat track/floor attachment vibration) of different body versions were assessed against that of baseline models. The conclusions would determine the seat contribution (seat/floor coupling) for body/vehicle NVH performance. The results would also guide the seat modeling methods for body/vehicle NVH CAE analysis.