Parametric analysis of the effect of CRS seatback angle in dummy measurements in frontal impacts

The  objective  of  this  study  was  to  assess  the  effect  of  modifying  the  seatback  angle  of  a  Child Restraint System (CRS) in the dummy readings and in the associated injury criteria in frontal impacts, performed according  to  the  specifications  of  the  regulation  UN  R129.  A  multibody  model  of a CRS was developed  an validated using the experimental results obtained in a frontal impact of a commercial rear?facing infant seat (45?86 cm) using the Q1.5 dummy. Then, the seatback angle of the CRS was virtually modified in the multibody model of the CRS between %2B10 degrees (more vertical) and ?10 degrees (more horizontal) at 2.5 degrees intervals. The average CORA rating resulted on a fair score (0.611 average rating) of the dummy readings. The modification of the seatback angle showed that there is a trade?off between the forces and moments acting on the cervical and the lumbar areas of the spine. Although a more vertical configuration resulted in an improvement of the of criteria specified by the regulations (average 15 reduction using %2B10 degrees), spine loads resulted on values three times higher than the reference configuration. Further research is needed to assess if the lumbar spine loads may reach injurious levels for these reclined postures.