Load Distribution Optimization of Seatbelt Using Validated Finite Element Approach

The seat belt system is one of most important component of the safety instrument family in a vehicle. The main purpose of seat belt is to minimize the injuries by preventing the occupant from impacting hard on interior parts of the vehicle and also the passenger from being thrown-out from the vehicle in case of rollover accidents. The standard three-point belt is mounted in the vehicle at three locations namely Anchor, D-ring and Buckle. The position of anchorages is very important to distribute the impact load evenly to the occupants. Very high load in any of these locations could cause breakage of the mountings and also concentrated loading on the occupant chest of pelvis. Current study mainly focuses on the seatbelt assembly performance improvement against UNECE-R16 sled test. The sled test was carried out first using 28g peak acceleration pulse and measurement of forces at shoulder and anchor position was measured using the load cell. FE (Finite Element) model of the complete seatbelt assembly was developed including Buckle, Retractor and Anchor plate. The simulation was carried out using TNO-10 R-16 dummy with the given position of D-ring, Buckle and Anchor plate. First correlation was established between the forces at shoulder location, Anchor plate location. Further correlation was established in the pelvis and thorax displacement. Multiple iterations were performed with the different position of anchorages in a given range in the validated model of seatbelt. The results showed significant effect of the Buckle and Anchor position in the force distribution on the dummy.