A Multi-Scale Head Crash Analysis by Employing an Experimental Measurement Based 3-D Micro Nerve Cell FE Model

The objective of this study is to establish a prediction method of the head crash injury at the nerve cell level by employing the stress and strain based criterion. We focus on the diffuse axonal injury (DAI) as the nerve cell injury. We employ the multi-scale finite element (FE) code to analyze the stress and strain responses by using the macroscopic brain model and microscopic cell model. A three-dimensional microscopic nerve cell FE model is built by employing measured results of PC-12 cultured nerve cells. When human head is crashed through the translational acceleration in traffic accident, the human brain is damaged at the crash side and the counter side, such as the coup and the contre-coup brain injuries. At the microscopic scale, numerical results show clearly that a very high equivalent stress, which means high tensile and shear stresses, occurred at the part of nerve axon. It was confirmed that our multi-scale FE analysis could predict the DAI by employing the critical injury stress and strain criteria at both macro and micro scales.