CAE Based Development of an Ejection Mitigation (FMVSS 226) SABIC using Design for Six Sigma (DFSS) Approach

NHTSA issued the FMVSS 226 ruling in 2011. It established test procedures to evaluate countermeasures that can minimize the likelihood of a complete or partial ejection of vehicle occupants through the side windows during rollover or side impact events. One of the countermeasures that may be used for compliance of this safety ruling is the Side Airbag Inflatable Curtain (SABIC). This paper discusses how three key phases of the optimization strategy in the Design for Six Sigma (DFSS), namely, Identify; Optimize and Verify (I_OV), were implemented in CAE to develop an optimized concept SABIC with respect to the FMVSS 226 test requirements. The simulated SABIC is intended for a generic SUV and potentially also for a generic Truck type vehicle. The improved performance included: minimization of the test results variability and the optimization of the ejection mitigation performance of the SABIC.

Results from this study show that for generic SUV and Truck type vehicles with hardware similar to that tested in this study;

• Beltline overlap, loft size and pressure account for 75% of the variability in performance of an ejection mitigation SABIC. These metrics may therefore be considered critical to the design of the SABIC.
• The identified key metrics may be used to define nominal ejection mitigation SABIC design best practice for the generic SUV and Truck.
• An associated investigation during this study showed that a SABIC may shrink significantly when fully inflated. This shrinkage has the potential to move SABIC lofts away from the intended impact location.
• The CAE based DFSS process has the potential to significantly reduce SABIC development time and may potentially enhance product speed to market using virtual tool versus empirically based SABIC development approach.