PMC8173077_01
Construction of test object from principle investigators brain magnetic resonance imaging (MRI): (A) Axial section of principal investigators brain with measurements of length scales of width, length, gyral thickness, gray matter thickness, sulci width, sulci depth, average skull thickness. (Not shown is coronal section to determine height length scale). Using obtained length scales from axial section, CAD developed canonical axial brain slice. (B) This axial brain slice was visually compared to original axial slice to ensure gross representation of dominant length scales, then slice was extruded to match the height of human brain. (C) This extruded axial prism was meshed to create three dimensional test object. (D) Results presented are two dimensional projections of the element values from the mid-plane of test object.
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F1
A three-dimensional (3D) geometric representation was derived from an idealized human brain axial section as depicted in Figure 1. See Figure 1.
Surrogate head model and embedding finite element solver into gas dynamics solver.
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F2
We did not include separate tissue models for vessel walls, thus our model of vascular structures contained only a fluid filled cavity embedded within the brain model, see Figures 2 and 5. The Sierra Zapotec tool couples the air blast in CTH to the finite element simulation in Sierra Solid Mechanics yielding a powerful yet scalable computational framework capable of simulating highly resolved computational meshes Figure 2.
Simulation scenarios of front, side, and wall blast. Later time simulation of wall shown to highlight complexity of reflected waves between skull and head.
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F3
Three blast scenarios were simulated (see Figure 3), front blast, side blast, and wall blast.
Vascular simulation results at 2.5 ms. (A) Cross-section of vascular model. Highlighted are the vessel models of diameters of 0.6, 0.8, 1.2, and 1.6 mm. Vessels are numbered from lateral to medial position. (B) Shear strain maximum in early time simulation. (C) Shear strain rate in early time simulation. (D) Intravascular cavitation events of 0.6 mm vessel -position 6 (top). Focal strain rates within vessel wall (bottom). (E) Total vessel cavitation volume as function of position and diameter. (F) Percent of vessel volume cavitation as a function of position and diameter.
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F5
We did not include separate tissue models for vessel walls, thus our model of vascular structures contained only a fluid filled cavity embedded within the brain model, see Figures 2 and 5.