A contact problem of bending of two beams with the internal joint

The joint bending of two Bernoulli–Euler’s beams is considered. Each beam has one end fixed and the other free. The beams have the different lengths and thicknesses. The long beam is loaded by the concentrated force. This beam is composite as it includes the internal joint. There is the frictionless unilateral contact between the beams. The elastic lines of the beams are to be found. This problem is reduced to finding of the density of forces of interaction between the beams and the constant that describes the unknown term in the displacement of the unrestrained part of the composite beam. The mathematical formulation of this contact problem is propounded. The density is assumed to be the sum of piecewise continuous function and delta-functions describing the concentrated forces. The uniqueness of the solution of the problem is proved and the analytical solution is constructed. Two possible contact patterns are found out. The former is contact at one point at the end of the short beam. The latter is contact at the same point and at one more point located at the unrestrained part of the composite beam. The coordinate of this point is the root of the cubic equation. The obtained analytical solution is used for the optimization of the structure. The optimization problem is to find the beams thicknesses that minimize the maximum stress for the given loading, beams lengths and the overall deflection. This problem is solved numerically for some values of the given parameters. The hypothesis of the equal-stressed optimum structure is set up on the basis of the numerical results. This hypothesis enables to construct the analytical solution of the optimization problem.

Application of the dynamic Lorentz model to modeling the motion of a rigid body

A qualitative research of the field of phase trajectories of the system of dynamic equations of an absolutely rigid body was carried out, moving around the selected pole under the influence of gyroscopic, dissipative forces and Coriolis inertia forces. The equations of body motion are reduced to a dynamical system generating a Lorentz attractor. Under parametric constraints imposed on the equations of a dynamical system, the structure of its phase trajectories is described depending on the values of the system parameters.

Import substitution in the field of telecommunications and IT technologies

The article examines the problems that arise when solving the problem of import substitution in information systems that work in the interests of state authorities. The tasks of import substitution in the field of information technologies are formulated. The causes of the problem are analyzed. Possible ways of solving the problem are suggested.

On algebraic integrals of equations of motion of a complex mechanical system

Criteria for the existence of certain types of algebraic first integrals of the equation of motion of a mechanical system of variable mass composition and variable configuration are given. The carrier body of the system (base body) rotates around a fixed pole in a stationary homogeneous gravity field under the influence of specified nonstationary forces. The types of partial integrals are indicated and restrictions are established that determine their existence.

Development of software application for network traffic analysis and intrusion detection

This paper demonstrated the use of neural networks in the development of network intrusion detection systems, described the structure of the developed software application for network traffic analysis and network attacks detection, and presented the software application results.

Learning programming of micro-controllers in CAD Proteus

The creation of projects in the Proteus program based on microcontrollers is considered. A classic 8051 microcontroller from Intel is investigated, as well as an STM32F401RE microcontroller from ARM. The development of the simplest programs for use in laboratory classes on programming embedded systems (for example, the "Internet of things") for 8051 – in assembler language, for STM32F401RE – in C language using a special development environment is carried out. The research can be used in laboratory classes on embedded systems programming.

Software code migration strategy from monolithic architecture to microservices

The purpose of this work is to describe a strategy that can help enterprises transition from a monolithic application code architecture to a microservice architecture. Using this migration strategy, the new system will receive a number of pre-assets offered by the microservice architecture, such as scalability and repairability. Companies will be able to migrate their older systems to more flexible systems, while increasing the performance of their software.

Mathematical models of centers of equal pressure in stellar systems

Mathematical models are proposed that allow calculating the coordinates of the centers of equal pressure in stellar systems and solving the inverse problem of determining the radiation sources of a material substance during the formation of macro-bodies. It is shown that the solutions of direct and inverse problems are not unique.

Differential equations of the start of motion of elasticly coupled inert bodies on the example of a train with elastic couplings

The starting mode for a ground vehicle is the most difficult. An effective way to pull off a train is to select coupling clearances. In this case, the cars are set in motion consequently, and the inert mass, as well as the static friction force immediately at the moment of starting, are minimal. This method, however, has two significant drawbacks – a small fixed value of the gaps in the couplings, which limits the effectiveness of the method and the shock nature of the impulse transmission, which negatively affects the state of the structural elements of the train. These disadvantages can be avoided by using elastically deformable couplings. The aim of this work is to construct a mathematical model of "easy" starting of a train with elastic couplings. The softening of the starting mode of the train is essentially due to the replacement of the simultaneous starting of the sections with alternate ones.

Features of using the viscoelastic material model in the ANSYS software package

The paper presents an experiment on uniaxial cyclic stretching with increasing amplitude of a filled elastomeric material. Such materials have complex mechanisms of mechanical behavior, in addition to elasticity, there are viscoelasticity and the Mullins softening effect. According to the experimental data, a mathematical model of a viscoelastic material with a softening effect is constructed in the ANSYS software package. It is shown that the combined use of the Ogden hyperelastic model, the Ogden–Roxburgh softening model, and the Prony viscoelastic model in the ANSYS software package accurately describes the mechanical behavior of the material for a multiplicity of elongation 2.