The ANCAP (Australian New Car Assessment Program) have been conducting offset frontal crash tests into a deformable barrier since 1995. During this time the results of the ANCAP tests have shown significant improvements in occupant protection measured via reduction in dummy injury measurements, i.e. HIC, chest ‘g’, etc.

Occupant protection has improved with manufacturers designing structures to minimise the occupant space intrusion with the aim to have the crash energy absorbed by deformation of the frontal vehicle structure. Also new restraint technology has been included along with the vehicle structure designed to optimise the restraint technology.

Previous analyses have questioned whether changes in the vehicle structures and restraint technology have changed the loads either in the occupant compartment or on the front seat belts. The previously analysis of ‘B’ pillar accelerations and also the front seat occupant seat belt loads for frontal crash tests performed by ANCAP from 1995 through to 2003 showed that while the dummy injury measurements have reduced there has not been a corresponding reduction in either ‘B’ pillar accelerations or seat belt loads.

This result was surprising given the occupant gains made through this period. It is possible that the regulatory and consumer crash tests and scoring parameters are such that vehicle engineers find it more efficient to optimise the restraint systems without significantly engineering the crumple zone.

However, the previous study did show small improvements in 'B' pillar decelerations in the small car segment (i.e. kerb weight of up to 1250kg). This study used data from other consumer crash test programs to add to ANCAP data to allow for analysis of a greater number of vehicles. This will be used to identify trends in energy absorption performance in the small car fleet.

The 'A' pillar displacement was used as an indication of load paths and also occupant cell structural integrity. The longitudinal acceleration time traces for driver side ‘B’ pillar will be used to represent the loads on the vehicle structure and correlated with seat belt loads and dummy acceleration measurements. It is intended to determine if crumple zones have been optimised with respect to the restraint system timing.