Simulation of Structural Latches in an Automotive Seat System Using LS-DYNA

Latches play an increasingly vital role in an automotive seat system due to the recent introduction of the mandatory 3-point restraint system for center occupants. Traditionally, latches were designed to carry the seat back load, the head restraint load, and the luggage intrusion load. For the new Seat Integrated Restraint (SIR) systems, latches have to meet a very high load requirement with a very low range of allowable displacement. Hence, a latch has to meet its basic function, which is to fold and tumble, and it has to pass this stringent non-linear loading condition. Finite Element Analysis (FEA) has been widely used to simulate latches on a component level. With the introduction of the displacement requirement limitation for the SIR retractor, component level analysis is redundant. The paper discusses an efficient new method to simulate the seat system along with latches that yield meaningful results and a consistent level of correlation.