LS-DYNA Based Optimization to Satisfy FMVSS 207/210

FMVSS 207/210 relates to seat system forward longitudinal strength and is one of the most important safety requirements for seats. Seat performance to satisfy FMVSS 207/210 can be simulated using LS-DYNA FEA code. When developing a seat design there is often a need to optimize the design to satisfy requirements/meet targets and to minimize weight. However LS-DYNA does not have optimization capabilities. This paper shows how the response surface based optimization can be used to meet FMVSS 207/210 requirements and reduce weight. A number of DOE runs are performed with different combinations of upper/lower/baseline gages. Data are collected for the maximum Von Misses stress and maximum effective plastic strain in each of the major seat parts along with the total weight of the seat. Based on the collected data the response surfaces are generated using Gaussian Stochastic Kriging method. Next the optimization is performed to minimize the weight of the seat while reducing the maximum stress and strain below the allowable value. The methodology has been demonstrated to improve the design of two different types of seats: a 20% front center seat and a rear seat.