This paper describes the first steps carried out in a joint effort of Ifsttar and Toyota to contribute to the development of a new abdomen for THOR dummy. Firstly, a review of accident data showed that abdominal injuries observed in frontal crashes were mainly caused by the steering wheel and the seat belt. However, abdomen injury rate was higher for side impacts, showing the importance of being able to predict such injuries for different impact angles. The steering wheel was mainly associated with injuries in the upper abdomen (liver and spleen injuries) whereas the seat belt was mainly associated with injuries to the lower abdomen (intestines). The former ones were well correlated with rib fractures and it was concluded that thoracic injury prediction could also give an indication of upper abdomen injury risk.

Secondly, existing abdomen designs were studied to rate technical solutions and orient future design. Notably, several technical solutions including external or internal pressure, force and deflection measurements were considered for the evaluation of abdominal injuries in the last past years.

Finally, all the conclusions were gathered in a design brief.

Before modifying the THOR abdomen, the biofidelity of different existing THOR abdomens was evaluated through impactor and static seat belt tests. None of these abdomens were able to fully meet the biofidelity corridors. These results represent the starting point for future modifications of the THOR abdomen response.