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The results of numerical modeling of the interaction between a cylindrical titanium impactor and heavy reinforced concrete barriers with steel rebars, using their different mutual positions (configurations) and a number of rebar diameters, are presented. The numerical simulations are performed using the finite element method in a three-dimensional formulation with the EFES software package developed by the authors. The Johnson-Holmquist model, which accounts for plasticity, crack development, and damage accumulation in the material, is used to describe the reinforced concrete destruction. The influence of the reinforcement geometry and configuration on the barrier destruction behavior, the extent of damage, and the impactor residual velocity is examined. These results can be used to optimize the design of protective structures made of heavy reinforced concrete.

The paper investigates the interaction of a steel striker with a three-layer target barrier. The barrier had three layers: ceramic, orthotropic organoplastic, and aluminum. The interaction velocity was 841 m/s, and the initial interaction angles with the barrier surface were set normal and 45°. The study is carried out numerically by the finite element method in a three-dimensional setting using the computer complex EFES developed by the authors. An elastic-brittle model is proposed to describe the behavior of the composite. A tensor-polynomial criterion of the second degree is used for the composite fracture. To describe the fracture of the orthotropic material of the target barrier, a two-stage model is proposed. The model of the composite behavior takes into account different strength moduli in compression and tension. As a criterion for the ceramics fracture, the deformation criterion was used. The behavior of the striker material and the metal layer are described by an elastoplastic medium, for the fracture of which a deformation criterion is proposed based on the limiting value of plastic deformation. The influence of the layer arrangement and initial interaction angle on the fracture of the target barrier has been studied.

The paper investigates the normal interaction between the steel striker, carbon fiber and aramid fiber reinforced plastic plates at a speed ranging from 166.6 to 184.2 m/s. A series of physical and numerical experiments with impact load is conducted to design a mathematical model and numerical algorithm for the composite plate. The behavior and fracture of composites are described by the elastic-brittle model accounting for their different compressive and tensile strengths. The numerical simulation utilizes the finite element method in the EFES software developed by the authors.

The approaches to implementing the algorithm of non-reflecting boundaries are considered. A damping layer is introduced and two different approaches are discussed: stress damping and force damping. In each approach, different distributions of the damping coefficient over the layer thickness are used: linear, quadratic and cubic. It is shown that the force damping using quadratic dependence is the most suitable approach.

The normal interaction of a steel striker with a composite metal-ceramic barrier is modeled numerically using the finite element method. The barrier consists of the following materials: boron carbide (B4C), aluminum, and orthotropic organoplastic. The behavior of metallic materials and ceramic B4C is described by an elastic-plastic model. The fracture criterion for metallic materials is the limiting value of the plastic strain intensity. The ceramic fracture is described using the deformation criterion accounting for different strengths in compression and tension. The behavior of the orthotropic composite is modeled as elastic-brittle, and the fracture of the organoplastic is described using the second-degree Hoffmann tensor-polynomial criterion. Numerical experiments are carried out using the software complex EFES. The model for boron carbide behavior during impact is validated. The influence of the striker rotation and arrangement of materials in the barrier on its protective properties is investigated.

In this study, a three-dimensional finite element analysis is performed to investigate the stress-strain state and failure of the anode block of a medium-temperature fluoride electrolyzer under cyclic high-intensity thermal loading, considering variations in the heating and cooling rates. It is assumed that the porosity within the coke plate is distributed in a random fashion. The modeling is conducted within the framework of a phenomenological approach in the mechanics of deformable solids. The behavior of the metallic elements of the anode block is described as an elastic-plastic medium, with the failure criterion based on the critical value of plastic strain intensity. The coke plate is modeled as an elastic-brittle medium, and its failure is described using a tensorial polynomial criterion that accounts for the differences in the coke strength values under compression and tension. The numerical simulations are performed using the EFES 2.0 proprietary software package. The influence of the heating rate of the anode block on the failure of the coke plate is investigated.

The interaction of space debris with the protective shield in the impact velocity range of 2 000–7 000 m/s is numerically simulated. The space debris particle is modeled by a steel ball. Numerical modeling is performed by the finite element method implemented in the author’s software package EFES. The proposed fracture algorithm allows describing the fragmentation of the material and the formation of new contact boundaries without distorting the computational mesh. The peculiarities of shock-wave processes and fracture of the screen and particle at different interaction velocities are investigated.

An algorithm for erosive fracture of solid bodies during high-velocity interactions is presented. The algorithm is implemented using the finite element method. The proposed mechanism for describing erosive fracture and restructuring of the computational mesh ensures the conservation of mass law. To accelerate the data preparation for the erosive fracture algorithm, optimization of the algorithm for searching adjacent element faces has been performed.

Interaction of elongated cylindrical strikers made of tungsten alloy VNZh90 with a finite-thickness plate made of the D16T aluminum alloy is numerically modeled. The influence of the shape of the head of the striker on the process and the result of interaction is investigated. Interaction velocity range 300–600 m/s and interaction angles from 0 to 75 degrees are considered. The behavior of the materials of the striker and barrier is described by an elastoplastic model. Limit value of intensity of plastic deformations is used as fracture criterion. Modeling is carried out in a three-dimensional setting using the finite element method using the author's algorithm and the EFES 2.0 software complex, which allows modeling the fragmentation of interacting bodies with the formation of new contact and free surfaces, erosion fracture of materials. The adequacy of the mathematical model and numerical algorithm is confirmed by the good agreement of experimental and numerical results. The interaction of the striker with the flat and cone shape of the head part with the barrier was investigated, the conditions under which the striker ricochets off the barrier were determined.

The normal interaction of ice particles with a composite orthotropic organoplastic plate is modeled scientifically. The range of interaction velocities from 80 to 500 m/s is considered. To develop a mathematical model and numerical algorithm, a coordinated series of physical and numerical experiments have been conducted on impact loading of the composite plate with steel spheres. The behavior and fracture of the composite and ice are described by the elastic-brittle model taking into account their different strengths in compression and tension. Numerical simulation is carried out by the finite element method using the software complex EFES developed by the authors. The composite plate fracture under simultaneous impact by a group of particles and sequential impact by a particle stream is investigated.