인체재료 모사 기반 충격 타박상 응력 예측 및 위협인자의 영향도 분석

Abstract

In various violent crime cases, blunt instruments accounts for approximately 50 % among direct hit criminal tools, causing injury, especially bruising, in the event of a physical impact. In this study, the prediction of bruising stress and the influence of the blunt instrument in terms of diameter and aspect ratio of bruise was analyzed based on the human material mimesis. Two material behavior models (quasi-linear viscoelastic model and Ogden model) were verified for human material mimesis. A finite element analysis in relation to the impact was performed according to diverse threat factors, and the influence of threat factors on the bruise were elucidated via an analysis of variance. As a result, the difference between the results of the finite element analysis and those of experiments reported in references was an average 11.7 %. Therefore, it was confirmed that the quasi-linear viscoelastic model and the Ogden model described the behavior of human material adequately. By comparing the bruise diameters obtained from the finite element analysis with the those in references, it was found that the bruise occurred when 23~30 MPa of von Mises stress was applied to the epidermis and dermis. In addition, the velocity of the blunt instrument was the most dominant influencing factor to the diameter of the bruise whereas the shape of the blunt instrument had the greatest effect on the aspect ratio of the bruise. It is believed that the range of the bruising stresses presented in this study may help predict and identify bruise in body, and an analysis methodology between the threat factors and the bruises based on the statistical technique can be utilized as a generic technique of forensic investigation.