Innovative Knee Airbag (KAB) Concept for Small Overlap and Oblique Frontal Impacts

Considerable research has been conducted in terms of attempting to reduce lower leg injury risk in full frontal impacts, in some cases by the use of a knee airbag (KAB). However, there has been limited research into the performance of KAB systems during a crash test with increased oblique loading, such as the IIHS small overlap frontal test, an oblique moving deformable barrier test (OI) being researched by NHTSA, and a mobile progressive deformable barrier test (MPDB) that is expected to be implemented by Euro NCAP in the next few years. The objective of the current numerical study was concentrated on the evaluation of an innovative KAB concept design intended to reduce ATD right inboard lower leg/foot responses under small overlap and oblique loading conditions. A novel appendage KAB concept design was developed with the help of morphing and computational studies which were performed with different ATD sizes. In the study, one of the lower leg/foot responses was monitored and compared over a conventional KAB design. Cases investigated in the study showed that the novel appendage KAB concept design acts as a conventional KAB in full frontal impact modes (similar right inboard femur responses) and has the potential to reduce right inboard lower leg/foot responses by an average 16% (small overlap impact mode) and 20% (oblique impact mode) over the conventional KAB design. Furthermore, it was noted that the novel design could potentially be adapted to achieve targeted right inboard lower leg responses in full, offset and oblique frontal crash tests with minimal impact on the left outboard responses.