Investigation of head injury criterion and its prediction capability under different cases of crash

Lecture / Panel
For NYU Community

Mechanical and Aerospace Engineering Department Seminar Series


Investigation of head injury criterion and its prediction capability under different cases of crash

Shahab Mansoorbaghaei
NYU Tandon School of Engineering

The Head Injury Criterion (HIC) is a measure of traumatic head injury arising from an impact involving translational acceleration. This equation has been widely employed to predict the head injury for accidents. Some investigators have reported and published some papers for the shortcomings of the HIC regarding angular accelerations, head mass and the exact threshold of injury level.
In this study, the Head Injury Criterion (HIC) has been critically analyzed and investigated for different head accelerations. Specifically in this research, when the head is subjected to different acceleration pulses, having the same HIC values and pulse times, the strain in the brain were investigated. Particularly, the two acceleration pulses which have the same peak values; on the other hand, they have different corresponding times for maximum acceleration. The results reflect that the brain strains for the two approximately similar acceleration pulses which exactly have the same HIC values, are entirely different. Investigators have reported that when the strain in the brain exceeds a threshold of 10% to 15% it leads to a traumatic brain injury, so it is acceptable quantity to predict concussion. Therefore, it is further concluded that the head injury predicted by the HIC value is not a reliable measure of the brain injury. This is due to the fact that the two acceleration pulses with the same two characteristics (maximum acceleration and impact time) where the HIC values were equal resulted in different strains in the brain. That is, the strain value in the brain depends on when the peak acceleration takes place; advance or retard, during an impulse. This study criticizes the HIC equation which has been employed for head impact analysis and design of protection systems.

Shahab Mansoorbaghaei received his MS and PhD in Mechanical Engineering at University of Science and Technology of Iran (IUST). He has been a postdoctoral scholar at City College of New York of the City University of New York since 2012. His research interests are related to head impact analysis during car crashes and study of structures under impact loadings with emphasis on analytical approach. He has more than 20 journal and conference papers regarding solid mechanics and impact analysis. Dr.Mansoorbaghaei has been teaching several courses related to mechanical engineering since 2008. In addition, he has been teaching Dynamics and Mechanics of Materials courses at New York University (NYU) since 2015. He has experience in automotive industry, mechanical part design and manufacturing.