In this paper the hypothesis made was that the maximum value of the angle, in the x-z plane, between the lap belt and the pelvis during the time period when the belt force exceeds 3 kN is a measure of the lap belt slipping off the pelvis in a frontal impact. Five mechanical sled tests with the Hybrid III dummy were transferred into MADYMO. The aim was to obtain that angle with high precision. In MADYMO belt slip over the dummy pelvis was modeled by means of two orthogonal, translational joints on the right and left Anterior Superior Iliac Spine (ASIS). The results support the hypothesis. Results from subsequent simulations show that belt slack, velocity change, and initial knee angle are strongly related to the strongly related to the tendency for submarining. The conclusion is that the maximum belt-to-pelvis angle during the time span when the lap-belt force exceeds 3 kN can be used to estimate the tendency for belt slip onto the abdomen and submarining in mathematical simulations of frontal impacts.
Samenvatting