New methodology for improvement of helmet performances during impacts with regards to biomechanical criteria

In this study a new method for enhancing helmet performances during an impact is considered. In a first step an approved composite helmet finite element model is coupled with an anatomical head finite element model and is evaluated in terms of injury risks (risks of neurological injuries or subdural haematoma) under normative impact conditions (ECE 22.05 standard). Results show that the risk of head injuries is very high even if the considered helmet passes the standard. Thus a second step consists in proposing a new method for improving the helmet behaviour in case of impact by focusing on the outer shell characteristics and by assessing the head injury risk with the human head finite element model. A modal analysis of the entire helmet model is performed and makes it possible to define areas of the outer shell to be modified. Under standard impact conditions this new virtual helmet model conduces to a huge decrease of the head injury risk, both in terms of neurological injuries as well as in terms of subdural haematoma.

► An approved helmet is evaluated against biomechanical criteria under standard impact conditions.
► Results show that current helmets only protect a headform and not a human head.
► A new method based on modal analysis for enhancing helmet performances during an impact is proposed.