Establishment of Countermeasures in Side Impact by Simulations 931975

To check sharply increasing traffic accident casualties, activities have been underway to analyze accidents and develop safety equipment Automobile makers have placed a great emphasis on improving safety in collision. In this situation, a new side impact standard was introduced in FMVSS 214 in October 1990 and will be applied to passenger cars in 1993 model year. The standard requires an additional full scale dynamic test in which an aluminum honeycomb moving deformable barrier (MDB) simulating the front end of a car is crashed at 33.5 mph into the side of a standstill car at an angle of 27 degrees. The Side impact Dummy's (SID) Thoracic Trauma index (TTI(d)), which is the average of the maximum rib acceleration and the maximum lower spine acceleration, is limited to 90 g's for a 2-door passenger car and 85 g's for a 4-door car. The dummy's pelvic maximum acceleration must remain no greater than 130 g's for both types of cars. Because most compact cars have no more than 300mm crash space between the door and the dummy, this new standard is even more stringent than the frontal impact requirements. This is especially so for a 2-door car, of which lateral rigidity is normally lower than that of a comparable 4-door car, and there have in fact been few makes which met the new standard.

In order to ensure compliance with the new FMVSS 214. We have reviewed our conventional development method carefully so that necessary countermeasures for 2-door cars can be incorporated into prototypes and thus much time and money can be saved by avoiding unnecessary design reworks and retests. Previously, we used experimental methods to work out safety provisions on vehicles, but such methods could be time-consuming and expensive, and variations in test had to be always taken into account, often causing delay in engineering release for prototypes. Therefore, the method of numerical simulations was chosen to quickly perform a series of operations from factor analysis to verification of countermeasures worked out As a result goals were achieved in a relatively short time. This paper presents the method of numerical simulation.