Modeling of the Non-Auditory Response to Blast Overpressure. Calculation of theInternal Mechanical Response of Sheep to Blast Loading

摘要

Calculations are made of the intrathoracic pressure expected from blast loadingof sheep. A mathematical model of the chest wall and lung parenchyma have been formulated as a system of differential equations which include the effects of chest wall mass and resistance, density of the parenchyma and an adiabatic equation of state for air within the parenchyma. The differential equations are discretized as a system of nonlinear finite difference equations with the blast loading appearing as a boundary condition. This finite system is then solved on a computer using an implicit solution algorithm. Blast loadings used in the calculations are from field tests and correspond to animal response ranging from no injury to severe injury. Intrathoracic pressure in the esophagus and at four locations within the lung parenchyma, all in the approximate plat of the seventh thoracic vertebra, are compared with field test measurements for four occupational levels and four injury levels of blast overpressure. Keywords: RA 3, Numerical analysis, Differential equations, Weapons effects(Biological), Blast injuries, Non-auditory responses to blast overpressure, Thoracic injury. (JG)