Small Unsecured Objects Transported in a Vehicle and Their Impact on Human Head Injury– Blunt Injury Criterion Approach

The presented study deals with a familiar situation when unsecured objects are transported in a vehicle. Unsecured objects have a character of objects dedicated to daily usage – work purposes or personal purposes. That generally means laptops, cell phones, tablets, drinks in a glass bottle, objects for sports, and others. Objects of interest are considered stiff/rigid with an insignificant portion of deformability.

The study focuses on the interaction between unsecured objects placed inside a vehicle and vehicle occupants – if a traffic accident happens. If an unsecured object is randomly placed inside the vehicle's inner structure and the vehicle crashes into the barrier, the unsecured objects act like projectiles. These projectiles may, in some cases, interact with occupants' bodies. The interaction may cause, in specific cases, a severe occupant injury. Regarding the human body, the critical part taken for the study purposes is a human head – respectively rear part of a human head with a theoretically insignificant skin thickness. The blunt injury potential (when an unsecured object interacts with a human head) is calculated through Head Injury Criterion (HIC) and Blunt Criterion (BC). Blunt Criterion plays in the presented study a significant role because it serves as a HIC comparison and verification, and the inputs to Blunt Criterion must be carefully selected. If not, the correlation between Head Injury Criterion and Blunt Criterion is not adequately justified.The presented case study shows the selection of the proper and improper values for the Blunt Criterion computations and the influence of the selected values on obtained Blunt Criterion results.