不同形状、速度的小破片对狗软组织致伤特点

Wounding Effects of Small Fragments of Different Shapes and Velocities to Soft Tissues of Dogs

本文报告了重量相同(0.44克)、形状不同的四种小破片、射击156只狗后肢软组织的致伤效应,碰击速度708～1560m/s。实验表明,速度是致伤的重要因素。当实验条件一定时,能量释放与破片速度平方、阻力系数成正比,与破片断面比重成反比。因此,破片形状对致伤也有一定影响。本组四种形状破片的损伤程度,以三角形为最重,方形、圆柱形次之,钢球最轻。

The wounding effects of small fragments of the same weight （0.44g） but different shapes and at different impact velocities（708-1560m/s） on the soft tissues of the hind legs of 156 dogs were studied. The experiment showed that velocity was the major factor in causing wounds. For fragments of the same shape, the energy transmission, volume of woud cavity, sectional areas at entrance and exit, and amount of tissue that had to be excised increased rapidly, with increasing velocity. In particular, as the velocity reached about 1500m/s, shallow and wide wound tract was liable to occur, peripheral tissue lesion was relatively apparent, even extended to the whole leg, and the rate of occurrence of bone fracture was high. The wounding effect of the shape of the fragment closely related to its sectional specific weight（W） and drag coefficient（CD）. Given the weight of the projectile and the density and thickness of the tissue, the energy transmission （ΔG） was directly proportional to the square of the velocity and to the drag coefficient, and inversely proportional to the sectional specific weight of the fragment. Therefore, under certain conditions, reducing the sectional specific weight often increased the drag coefficient, in favour of causing a wound. In this experiment, the extent of wounds caused by the triangular, the square and the cyllndrical, and the spherical fragments decreased in that order, in agreement with their values of sectional specific weightand drag coefficient.