Drs. Arruda and Ashton-Miller have developed a two-dimensional (2D) skull/brain surrogate to examinethe 2D displacement fields in the brain as a function of impact location. From these fields they compute shear strains in the brain and rotational and translational accelerations. Their preliminary results show that the harmful effects of the impact depend considerably on the location of the impact force with respect to the center of mass of the head. In the proposed work, Dr. Arruda will build 2D prototypes of both existing helmet designs and her new design. These will be sized to fit around the skull/brain surrogate developed by Drs. Ashton-Miller and Eckner in a similar manner to how a helmet fits an actual skull. Dr. Arruda will work with Drs. Ashton-Miller and Eckner to conduct instrumented impact studies on the various helmets and determine the peak shear strains and peak translational and rotational accelerations experienced by the surrogate wearing each helmet. The expected outcome is that the helmet proposed by Dr. Arruda will reduce peak strains and accelerations in the brain over those seen with other helmets. A direct comparison will be made to validate Dr. Arruda’s computational model by simulating the actual 2D helmet and surrogate experiment.
Dr. Arruda’s helmet dissipates much of the energy of the impact before it is transmitted to the skull, and therefore, before it reaches the brain. Although we do not yet fully understand the injury mechanisms in the brain we do fully recognize that if you mitigate the harmful effects of an impact before it reaches the brain you will reduce the risk of injury.