Search Results

A mathematical treatment of inertial release of seatbelt buckles is presented, along with an exact criterion for belt release The model balances forces on each part of the mechanism to find their accelerations These accelerations are double integrated with respect to time to get displacements, and when these displacements reach certain values, the buckle opens Sample results are given for a common type of latch, and these results are compared to experimental results. The analysis shows that the acceleration required to inertially open a latch is an increasing function of the belt tension The shape and duration of the acceleration vs time pulse are also important.

This paper describes a linear acceleration sled device developed to study child responses to panic braking environments. A sled with a vehicle seat and soft simulated dash is accelerated by a drop weight in a similar fashion to actual vehicle decelerations when panic braking. A simple, two degree of freedom analytical model of the experimental device was developed to predict the dynamic performance of the sled and examine the sensitivity of various parameters in producing acceleration time histories of actual braking vehicles. This includes the study of drop weight size, drop weight distance, cable size, initial cable pretensioning and sled braking levels. A simple, two degree of freedom analytical model was also examined to simulate a child dummy sitting on the sled seat and verified by using actual sled acceleration-time pulses. The model was based on previously conducted vehicle braking tests with dummies and child dummy tests conducted on the linear acceleration sled device.