sp was determined based on the

Аsp was determined based on the method of continuous acceleration registration during reverse ballistic experiments. In order to determine the specific displacement work of material targets, the experiments on penetration of undeformable projectile (d0 = 0.005 m and beta adrenergic receptors λ = 10) were carried out. The nose part of projectile was a cone with α = 60°. The targets AlMn1 and D16-AT were 80 mm in thickness with Brinnell hardness of 30 MPa and 43.5 MPa, respectively. The obtained results are presented in the form of functional relations The critical velocity [7] is expressed as The value of critical velocity was determined from the hardness of the projectiles, which is equal to 663 mps for AlMn1 and 788 mps for D16-AT alloy. The functional dependencies for both alloys in the ascending branch of the curve (in Fig. 3) can be expressed with a second-order polynomial and have the following shape, for example, for AlMn1 After the maximal penetration is achieved in the deep layers of the target (h ≥ 2.5 d0), the specific displacement work stays constant (Fig. 3).
Penetration modeling In order to determine the amount of energy used on elastoplastic deformation Еep, the penetration of fluoropolymer projectile into semi-infinite aluminum-based alloys under the same experimental conditions mentioned above (Tables 1 and 2) was test. The projectile was considered an elastoplastic body, and no additional thermochemical energy was assumed to be released during the penetration. The calculations were made with the software package TIM-2D [8] designed for calculations of two-dimensional continuum mechanics problems on unstructured polygonal Lagrangian meshes with arbitrary number of connections Fig. 4.
Comparison of modeling and experimental results Figs. 5 and 6 show the cavities obtained in numerical calculations for different impact velocities and target parameters according to the von Mises model and Glushak model, respectively. Comparison of the results with experimental data (Fig. 7) shows that all models show a good agreement with experiment in the description of cavity diameter. It is possible to conclude that the cavity formation, especially at the initial stage of penetration, is caused only by projectile kinetic energy. Amount of additional chemical energy can be determined aswhere and are experimental and calculated cavity volumes, respectively. The calculated results for D16-AT are presented in Tables 3 and 4. In Table 3, the calculations labeled as “Glushak 1” were made with von Mises model for fluoropolymer with Y0 = 0.15 GPа and Glushak model for D16-AT. Calculations labelled as “Glushak 2” were made with von Mises model for fluoropolymer with Y0 = 0.35 GPа and Glushak model for D16-AT. Unfortunately, the format of the article does not allow to present a more detailed analysis of the calculations carried out with the models. However, the results shown in Fig. 6 show that the results calculated using these models have the same trend as those calculated using the basic model (Table 3). Analysis of the results (Table 3 and Fig. 7) shows that the proportion of the chemical energy decreases with the increase in the interaction velocity for all models, except Johnson–Cook model, which contradicts with physical concepts and experimental data [1]. In Tables 3 and 4: V0 is velocity of fluoropolymer penetration into the target mps; are experimental and calculated volumes of cavity, cm3; Ech is energy released by chemical reaction between fluoropolymer and aluminum of target, kJ; Glushak 1 is the elastic plastic states of fluoropolymer calculated by Mises model with Y0 = 0.15 GPa and AlMn1 calculated by Glushak model with Y0 = 0.18 GPa; Glushak 2 is the elastic plastic states of fluoropolymer calculated by Mises model with Y0 = 0.035 GPa and AlMn1 calculated by Glushak model with Y0 = 0.18 GPa. In other cases, the elastic plastic states of fluoropolymer were calculated by Mises model with Y0 = 0.035 GPa, and the elastic plastic states of AlMn1 and D16-AT were calculated by Glushak and J-Cook and Mises models.