Background. The goal is to demonstrate the features of terminal ballistics of gunshot and shrapnel wounds in an experiment using mathematical modeling. Materials and methods. Two samples of cylindrical damaging elements were used for experimental studies, namely preformed fragments with which high-explosive fragmentation warheads 9M55 of 122-mm high-explosive fragmentation unguided rockets 9M28F (9M28F-1) are equipped, and preformed fragments with which anti-personnel mines OZM-72 are equipped. Registration of the contact velocity of the damaging element before hitting the target was carried out using the optoelectronic measuring complex IBKH-731.4. Shots were fired at blocks of ballistic plasticine Weible with dimensions of 200… 250 200… 250 130… 200 mm. The distance between the muzzle of the weapon and the block of ballistic plasticine was 1.5 m. For comparison, experimental shootings were conducted at a block of ballistic plasticine with bullets fired from rifled weapons. Experimental shooting was carried out with a 7.62 mm TT pistol and a 5.45 mm AK-74M assault rifle using cartridges of the appropriate caliber. A mathematical model was constructed for computer simulation of the process of penetration of a solid steel impact element of cylindrical shape into a ballistic plasticine sample. The model had an axisymmetric form where the ballistic plasticine volume sample and the damaging element are cylinders. For ballistic tests with cylindrical preformed fragments, a set of field tests (firing) was conducted to assess the penetration of the damaging element with different initial velocities in the range from 70 to 1000 m/s. Similarly, a set of computational studies were conducted for cylindrical damaging elements with different velocities. Results. Comparison of the wound channel geometry (depth of penetration and maximum opening width) allowed us to select the parameters of the mathematical model, ensuring good convergence of the results of field tests and computer simulations. The graphs comparing the depth of the wound channel formed as a result of the penetration of a damaging element into ballistic plasticine, obtained experimentally and calculated from mathematical modeling, coincide. The results of the obtained computer simulations show the formation of a wound channel during damage by a preformed fragment and a bullet at the same time points and under the condition of the same initial velocity at the moment of impact. Cylindrical preformed fragment in all cases qualitatively exerts the same effect, forming a conical lesion cavity with the widest zone at the point of first contact of the element with the plasticine block. At the same time, the nature of the wound channel geometry does not depend on the velocity with which the damaging element enters the block of ballistic plasticine, and an increase in the velocity leads, in fact, only to an increase in the depth and width of the wound channel. As the penetration velocity increases, the bullet in all cases begins to lose the stability of its rectilinear motion inside the body and rotates significantly increasing the damage around it. In all cases, a wound channel with a significantly greater depth is observed in case of a bullet wound given the same initial velocity, which is obviously explained by its more streamlined shape and greater initial kinetic energy due to its slightly larger shape and mass. Another important observation is that at the point of penetration, the opening of the wound channel is always greater in case of using preformed fragments, while bullet wounds cause significantly more damage inside the body, which is manifested at moderate and high wound velocities and always have wound channels of greater depth. Analysis of the above results also shows that wound channels formed by a bullet at low impact velocities have greater depth but a smaller area of damage. This effect has understandable physics — at a higher penetration velocity, a long bullet loses its stability of rectilinear motion and rotates damaging a larger area and receiving significantly greater resistance from the environment, which determines its smaller penetration depth. Conclusions. Preformed fragments with cylindrical shape and small elongation behave stably in the thickness of the viscoelastic medium. In case of impact, they form conical cavities. The greatest damage is caused by cylindrical damaging elements in the first third of the damage channel. This is due to the almost complete transfer of their kinetic energy to the layers of the environment adjacent to the central damage channel in this zone. The dimensions of the damage zone in this section of the channel are maximum. With the loss of their kinetic energy, the damaging elements continue their movement into the thickness of the obstacle and cause minimal damage to the surrounding layers of the environment. When hit, preformed fragments do not deform or fragment, unlike bullets for rifled firearms, especially unlike bullets with a lead core or expanding bullets. The results of the experiments allow us to expand the possibilities of research not only into the features of wound ballistics of preformed fragments and fragments of ammunition and explosive devices, but also to determine the features of their movement in the air, which is of significant importance for studying external ballistics and determining aeroballistic characteristics. This, in turn, allows us to determine the size of the damage zones and safe distances. Mathematical modeling enables predicting the amount of damage caused by projectiles with different characteristics in the model. The results of mathematical modeling in the experiment show a fundamental difference in the amount of damage in bullet and shrapnel wounds, which should be taken into account during surgical treatment.
Лурін et al. (Tue,) studied this question.