An Assessment of Worldsid 50th Percentile Male Injury Responses to Oblique and Perpendicular Pole Side Impacts

Pole side impact crash tests are in use in regulatory and consumer programs around the world. There is some diversity in the test methods that are applied, including the suitability of available side impact dummies for use in these tests. For the WorldSID 50 percentile adult male dummy, much theoretical discussion has focussed on the likely rib response, including the direction of this response in oblique and perpendicular pole side impacts. With the advent of multi-dimensional rib deflection measurement systems, such as 2D-IRTRACC and “RibEye”, it is possible to investigate this question. This paper reports on a series of six vehicle-to-pole side impact tests conducted using a WorldSID 50 percentile male dummy on the struck side of the vehicle fitted with the “RibEye” measuring system for the abdomen, thorax and shoulder. In addition, a WorldSID 50 percentile male fitted with the conventional IRTRACC system was installed on the non-struck side. Two large Australian made passenger sedans were tested using three different pole side impact methods. The test methods investigated were a perpendicular impact aimed at the head centre of gravity, a perpendicular impact aimed 100 mm forward of the head centre of gravity, and an FMVSS 214 based oblique impact. All tests were conducted with an impact velocity of 32 km/h. Theoretical IRTRACC deflections are calculated from the “RibEye” data. The objective of this study was to evaluate the effect of pole impact angle and alignment on injury risk as predicted by struck and non-struck side WorldSID 50 percentile adult males. Important contributing factors to this response including the vehicle structural response, recorded airbag fire time, and airbag deployment characteristics are also analysed. Both vehicle models selected were fitted with combination head and thorax side airbags, but with different impact sensing systems. The vehicles also represented different generations of structural and airbag development. X and Y axis deflections are analysed in comparison with the calculated IRTRACC values. These show a distinct difference between perpendicular and oblique test configurations, and differences resulting from impact location. An additional factor is airbag deployment, as in some cases airbag entrapment resulted in differences in thorax and head response. Occupant-to-occupant interaction is also analysed, with this contact producing HIC36 results normally associated with a high probability of fatal head injury in five of the six tests conducted.