During impact on Soldiers’ heads, such as in behind-helmet blunt trauma (BHBT), skull fractures can indicate injury. We previously developed a concept for simulating skull fracture with an Elemental Approach using microstructure-inspired mechanism-based (MIMB) method, and simulated fracture patterns matched well with the experiment. However, application to BHBT simulations was hindered by the necessary use of relatively small elements and the deterministic nature of the simulations. Here, possible solutions were evaluated. The Three-Layer Approach represented the skull by a sandwich structure—defined previously as 70% bone volume fraction (BVF) thresholds—near impact and by a single homogeneous material elsewhere. New layering and improved failure algorithms were developed to aid BHBT researchers implementing this approach. Stochasticity was introduced by randomly redistributing element-BVF values within layers, providing a high- throughput method for approximating biovariability. The Three-Layer Approach satisfactorily represented the experiment’s load-displacement response, but skull failure occurred by different mechanisms dominating the final failure. In contrast, hybrid Three-Layer–Elemental simulations reasonably approximated both deformation and failure response, including the final dominant mechanism of failure, whenever the inner table was represented by the Elemental Approach. Initiated back-surface crack patterns from different stochasticities showed the method can evaluate probabilities associated with brain-injury scenarios from skull cracking.
2022-04-06 08:00:00
