Mathematical and finite element modeling of liver damage in high-velocity shrapnel injuries

Source abstract

Mathematical and, based on it, numerical computer modeling of liver damage by fragments has been performed with the help of the finite element method. The relevance of the work stems from the complexity of experimental study of dynamic destruction of human internal organs, in particular the liver. The purpose of the study is to create mathematical model and, based on it, to develop finite element model of the human liver taking into account the formation of damage in it from the high-speed action of fragments for analyzing the dynamics of deformation processes, the development and influence of shock waves on the formation of a wound channel in the liver and surrounding soft tissues, considering their physical and mechanical properties. A simulation of a shrapnel injury to the liver by fragments of various sizes and in the range of their movement speeds has been performed, which made it possible to reproduce the process of formation of a wound channel and penetration of a fragment into the tissues. It has been proven that a small fragment can reach the liver tissue at a speed of more than 550 m/s, and a large fragment — at a speed of more than 100 m/s. The stress-strain state and wave processes in the liver and the soft tissues surrounding it were studied. The maximum values of excess pressure arise in the area of fragment penetration and affect almost the entire organ, causing damage even in the absence of deep penetration of the fragment. At the same time, blind wounds and shock-wave lesions of the surrounding tissues prevail in small fragments, and large fragments cause both blind and penetrating liver wounds with significantly greater penetration depth and volume of tissue destruction. The work results will be useful for specialists and researchers in biomechanical modeling of internal organ injuries, assessing the severity of injuries, conducting forensic medical exa­minations, as well as for the further development of finite element models to predict internal organ injuries.