The Influence of Impact Angle on the Dynamic Response of a Hybrid III Headform and Brain Tissue Deformation

The objective of this study was to investigate the influence of impact angle on the dynamic response of a Hybrid III headform and brain tissue deformation by impacting the front and side of the headform with four angle conditions (0° at the impact site and 5°, 10° and 15° counter-clockwise rotations from 0°) as well as three additional angles of -5°, -10° and -15° (clockwise rotations from 0°) at the side location to examine the effect of direction. The acceleration-time curves were used as input into a finite element model of the brain where maximum principal strain was calculated. The results from this study show that impact angle has an asymmetrical influence on headform dynamic responses and strain. An increase in impact angle tends to result in a growth of headform linear and rotational acceleration and maximum principal strain for the front location as well as the negative angles (0 to -15°) at the side, however varying trends were observed for the positive angles (from 0° to 15°) at the side. When developing sophisticated impact protocols and undertaking head injury reconstruction research, it is important to be aware of impact angle.