Biomechanical responses of a pig head under blast loading: a computational simulation

Abstract

A series of computational studies were performed to investigate the biomechanical responses of the pig head under a specific shock tube environment. A finite element model of the head of a 50-kg Yorkshire pig was developed with sufficient details, based on the Lagrangian formulation, and a shock tube model was developed using the multimaterial arbitrary Lagrangian-Eulerian (MMALE) approach. These two models were integrated and a fluid/solid coupling algorithm was used to simulate the interaction of the shock wave with the pig's head. The finite element model-predicted incident and intracranial pressure traces were in reasonable agreement with those obtained experimentally. Using the verified numerical model of the shock tube and pig head, further investigations were carried out to study the spatial and temporal distributions of pressure, shear stress, and principal strain within the head. Pressure enhancement was found in the skull, which is believed to be caused by shock wave reflection at the interface of the materials with distinct wave impedances. Brain tissue has a shock attenuation effect and larger pressures were observed in the frontal and occipital regions, suggesting a greater possibility of coup and contrecoup contusion. Shear stresses in the brain and deflection in the skull remained at a low level. Higher principal strains were observed in the brain near the foramen magnum, suggesting that there is a greater chance of cellular or vascular injuries in the brainstem region.

Numerical simulations of the occupant head response in an infantry vehicle under blunt impact and blast loading conditions

“…In other words, the solid and fluid elements coexisted in the same space. The fluidsolid interaction (FSI) parameters used in this study were consistent with those in the study by Zhu et al 13,14 A parametric study was conducted on the number of coupling points (1, 2, and 3), and it has been revealed that the coupling points had little effect on the results. Therefore, to save computational cost, one coupling point was used.…”

The Mechanics of Traumatic Brain Injury: A Review of What We Know and What We Need to Know for Reducing Its Societal Burden

“…Species include rodents [109,128,135,138,140,143,144,[161][162][163][164][165][166][167], pigs [168][169][170][171][172][173], and sheep [174][175][176]. These experimental models offered a measure that human physical models and human surrogate tests often could not provide-an estimate of the injuries that occurred throughout the brain as a result of the mechanical loading.…”

Computational simulation of the mechanical response of brain tissue under blast loading

“…In the displacement-input simulations (e.g., from compression of the skull), less than 1% nominal strain at different rates was applied with a smooth prole that resulted in peak accelerations below and above the critical acceleration. In the pressure-input simulations (e.g., pressure wave passing through the scalp and skull), pressure pro- files reported in [22] for rat brain were selected as the basis and the peak pressure was scaled based on blast injuries reported in pigs [23]. Clearly for future studies directly measured boundary conditions that result in various degrees of BINT are needed.…”

“…In the second set of simulations, based on the experimental pressure measurements in a rat BINT model with BOP generated from a shock tube and pressures measured in the third ventricle [22], two pressure pro les were scaled and applied to the model. The scaling factor of the two pressure pro les were determined to give initial peak pressures ( p max ) according to the lower end (50 kPa) and mid-range (200 kPa) of the eld measurements pertaining to blast induced brain injury as a result of blast explosions [23]. …”