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

• Published in: International journal for numerical methods in biomedical engineering 2013-03, Vol.29 (3), p.392-407
• Main Authors: Zhu, Feng, Skelton, Paul, Chou, Cliff C., Mao, Haojie, Yang, King H., King, Albert I.
• Format: Article
• Language: English
• Subjects: Animals; Biomechanical Phenomena - physiology; Blast Injuries; blast simulation; Brain - anatomy & histology; Brain - physiology; Brain - radiation effects; Computer Simulation; Finite Element Analysis; Head - anatomy & histology; Head - physiology; Head - radiation effects; High-Energy Shock Waves; MMALE; Models, Biological; Pressure; primary blast TBI; shock tube; shock wave; Skull - anatomy & histology; Skull - physiology; Skull - radiation effects; Stress, Mechanical; Swine
• ISSN: 2040-7939; 2040-7947
• DOI: 10.1002/cnm.2518

SUMMARYA 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. Copyright © 2012 John Wiley & Sons, Ltd. Finite element modeling was conducted to simulate the shock wave generation, propagation and application on a pig head under a shock tube environment. Anatomical details and appropriate tissue properties have been included in the numerical pig head model, and the regional effect of pressure was studied after the numerical models were validated. Pressure enhancement was found in the skull, which is believed caused by shock wave reflection at the interface of the materials with distinct wave impedances.