Crash Pulse Characterization for the Passenger Vehicle Fleet in India.

A crash pulse is the signature of the deceleration experienced by a vehicle and its occupants during a crash. The deceleration-time plot or crash pulse provides key insights into occupant kinematics, occupant restraints, occupant loading and efficiency of the structure in crash energy dissipation. Analysing crash pulse characteristics like shape, slope, maximum deceleration, and duration helps in understanding the impact of the crash on occupant safety and vehicle crashworthiness. This paper represents the crash pulse characterization study done for the vehicles tested at ARAI as per the ODB64 test protocol. Firstly, the classification and characterization of the crash pulses is done on the basis of the unladen masses of the vehicles. The same are further analysed for suitability of mathematical waveform models such as Equivalent Square Wave (ESW), Equivalent Triangular Wave (ETW), Equivalent Sine Wave (ESW), Equivalent Haversine Wave (EHSW) as well as EDTW (Equivalent dual trapezia wave) or Bi Slope Approximation model for the characterization. These mathematical wave diagrams are then utilized for analysing the crash behaviour and its probable effect on the injury probability. Secondly, this paper characterises the crash pulse to produce the respective delta ‘V’ plots. An attempt is made to corelate the dummy injury parameters with these plots. The correlation is identified on the basis of the crash events resulting in according slope changes in the delta V plots. Such a study can be used by design engineers to model the front-end stiffness of the vehicle frontal structure. This can further help to optimize the dummy restraint modifications to minimize the occupant injury .