Hybrid Experimental Modeling Computational (HEMC) Skullcap Simulation: Elemental to Layer Simplification and Application to Microstructural Stochasticity
Abstract
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 percent 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 experiments 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 cracking.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2021
- Accession Number
- AD1148408
Entities
People
- Brian Fagan
- Stephen L. Alexander
- Timothy Baumer
- Tusit Weerasooriya
Organizations
- United States Army