Abstract— A device based on smart alloys has been designed for use in machine building items, in particular, in nuclear engineering, for preventing anthropogenic and natural emergencies. The device breaks the electric circuit by cutting the electric wire bundle in case of an emergency increase in temperature above the permissible limit.

Abstract The kinematics of the motion of floating elements (ring) of rotor mechanisms under steady state rotation modes is examined experimentally. The ring is placed with a gap with respect to the drive cylindrical link and touches it without losing contact. It is shown that the ring motion is a direct asynchronous precession and its points circumscribe epitrochoids, if the driving motion is “lunar

Abstract The effusion of gas through a small rectangular opening into a vacuum is studied using methods of mathematical modeling. The distribution functions of gas particles flowing out of an opening and the moments of these functions, i.e., fields of gas particle concentrations and velocities, are obtained. The dependence of effusion on the volume from which the gas escapes is investigated.

Abstract The use of mechatronic rotary linear modules in manipulators of machine-tool equipment is considered. A solution to the inverse position problem is presented, and the kinematic capabilities of a device based on mechatronic rotary linear modules for machine-tool equipment are evaluated. Dynamic equations have been derived used to evaluate the dynamic characteristics and the precision of the

Abstract In this paper, we consider the problem of calculating the parameters of damped oscillations under the collision of two systems with one degree of freedom. Such oscillations can be accompanied by vibroshock processes with repeated collisions (modes with bounce). The nature of these processes depends on the accepted models of energy dissipation and the design features of the colliding objects

Abstract The problem of calculating the reliability and fatigue life of machine parts by the fatigue failure under random changes in the actual and limit stresses is considered. According to the corrected theory of the linear summation of damage, a transcendental equation has been obtained that relates the number of cycles until failure to the random loading parameters and the ultimate strength. From

Abstract An analytical solution to the direct boundary-value problem and the two-dimensional problem concerning the stressed condition in the median surface of a step-shaped shaft is presented. In the boundary-value problem, a singular integral equation with the Cauchy kernel is used, the solution of which can be found in the form of an unlimited increase in stresses at the ends of the integration

Abstract In this paper, analysis of influence of residual stresses in the surface layer of cylindrical friction pairs on the operational wear resistance index is carried out. Stresses of the first kind after application of combined machining are investigated. Combined machining is consecutive electromechanical machining and diamond burnishing. A formula for calculation of residual stresses originating

Abstract The reliability of complex engineering objects is affected not only by the duration of the failure-free service (the continuous lifetime) but also the number of no-failure actuations to switch on the object into operation or switch it off (the discrete lifetime). The aim of this work is to fill this gap in part.

Abstract The dynamic characteristics of a saw gin as a subsystem with lumped and distributed parameters are considered in the paper. On the basis of investigation of the machine assembly, graphs are drawn that allow establishing the maximum values of the angle of relative rotation and the angle of rotation of the saw cylinder shaft under torsion.

Abstract In this paper, the results of full-scale experimental studies on the effect of the structural material strength of thin-walled cases of concentrated explosive charges on the performance of pulsating explosive devices for various purposes are analyzed.

Abstract— A method of design analysis of a magazine ring and wave band springs of unidirectional, high strength, and low modulus fiberglass is represented. The springs are intended as a spring suspension for vehicles and aircraft. The use of split rings with different gaps makes it possible to obtain a nonlinear change in the compliance of suspension. The effects of the creation of equal strength profiling

Abstract An assessment method for characteristics of low-rate development of fatigue cracks under operational loading is proposed. The method is based on the decrease in the irregular loading level by conservation of its conformity during crack growth. The control factor of the loading decrease is the intrinsic increase in the compliance of a sample during crack growth by its fixed opening. The experimental

Abstract This article gives a review of three approaches to solving the problems of detecting local rod and pipeline defects and related problems. In the first approach, local defects are modeled by the matching conditions; in the second approach, by delta functions entering into the differential equation; and in the third approach, longitudinal cavities and cracks are modeled by continuous rod sections

Abstract A systematic study of the effect of energy dissipation on critical nonconservative loads within the stability calculation is carried out. Some classical nonconservative elastic stability problems are considered: the stability of a linear form of equilibrium of a double pendulum under the action of a follower force, the stability of a cantilever beam compressed by a follower force (Beck’s problem)

Abstract A numerical-analytical method is proposed for calculating the forced vibrations of a shell structure immersed in liquid. The structure is a set of finite elastic cylindrical shells and elastic rings to which concentrated discrete forces are applied. Examples of a comparative calculation of the frequency response and vibration modes of the shell structure in a vacuum and in liquid are given

Abstract A frictional self-oscillating system with an elastic force delay and external influence is considered while interacting with an energy source of limited power. The procedure for using direct linearization methods to calculate mixed forced oscillations and self-oscillations in a system with delay and limited excitation is described. Based on this procedure, equations of nonstationary and stationary

Abstract This article presents a method for the analysis of diagnostic acoustic signals for defect detection in composite materials. For this purpose, a multiple-scale decomposition of the acoustic signal and the determination of informational entropy for its components are used. It is established that, in the presence of small defects, the distribution of the power spectral density is little different

Abstract Shaping by means of reeling under the conditions of superplasticity using specialized reeling mills is a promising technology for manufacturing axisymmetric parts of gas turbine engines (disks and hollow shafts) based on heat-resistant alloys. Mathematical simulation is an efficient method for determining the energy and thermomechanical parameters of the technological process. This paper describes

Abstract In this paper, studies aimed to substantiate the directions of improving the reliability of a metal-cutting tool with working parts modified in terms of its service life by application of low-temperature plasma are presented. These investigations employed a database generated by the results of the pilot production operation of a modified hard-alloy tool and the mathematical software developed

Abstract In this article, the reliability of a gear–motor system is analyzed on the condition that the failure of the gear leads under certain circumstances to the failure of the motor. The states of the system are modeled by a continuous-time Markov chain. The resulting system of differential equations is solved using the Laplace transform. In this way, the probabilities of the system’s states can

Abstract The effect of combined surface hardening such as electromechanical treatment and surface plastic deformation exerted on inelastic deformation processes occurring in grade 45 steel has been studied. The results of tensile tests and the analysis of the mechanical hysteresis loops for samples of grade 45 steel subjected to combined surface hardening are presented. The characteristic features

Abstract A methodology for simulating mathematically the limit states of machines and structures subjected to quasi-static operational and shock impacts is generated by considering great (final) deformations and degradation of the properties of materials. The known experimental results and the modern mesomechanics conceptions on the structure, damage, and nonlinear processes of viscous-plastic faults

Abstract A technique is presented for studying two batches of alloys based on Ti and Ni having the shape memory effect, with the help of which the deformation characteristics were obtained for samples of the alloy. Based on the results obtained, the use of alloys with different deformation characteristics for improving the reliability and tightness of pipeline junctions using alloy couplers with the

Abstract This article considers aspects of thermomechanical processing at T > 400°C of Ti and Ni alloys with shape memory and the properties of materials with thermal elastic transformations, depending on the thermal and thermomechanical action as well as the aspects of thermal processing of metals with thermoelastic transformations. Technologies are proposed for applying thermal processing to alloy

Abstract This article examines the aspects of power in-process operations along automatic lines for filling and packaging liquid and half-liquid products. It is shown that individual power station actuators can be replaced with one group air hydraulic actuator without any loss in productivity. Moreover, the dynamics of cutting out ready-made items can be significantly improved. The layout of an air

Abstract For a reasonable and reliable assessment of durability at the design or operation stage of the tracked vehicles, it is required information about the loading process. For a reliable assessment of loading and, consequently, durability, the question arises about the representative length of the loading process recording. The paper proposes a method for determining the necessary and sufficient

Abstract This paper presents the results of experimental studies on the process of thermal drilling in workpieces made of barely deformed alloys by the example of the alloy HN62VMYuT-VD. A comparative analysis is presented, and the modes efficient from the standpoint of thermal drill wear and the process productivity are demonstrated. In addition, the revealed geometrical parameters and material of

Abstract This paper considers a method of determining the stiffness and displacement of the output link of a tripod robot that is a part of a robotic system with relative manipulation modules based on a Jacobian matrix. It shows that the stiffness maps reveal the maximum and minimum stiffness in the robot workspace. An algorithm for calculating the error caused by the displacement of the output link

Abstract This article discusses wear-preventive tribological coatings that increase the operational life of artillery, tank, and rifle barrels. Studies have been conducted using some of them. The presence of a sufficiently large scientific and technical reserve in the field of material science of heat-resistant alloys and antifriction antiwear coatings is noted.

Abstract Based on computational and full-scale experiments, several algorithms have been developed for processing current–voltage curves obtained for flat wall and remote probes in the case of a weakly ionized low-temperature collisional plasma. The proposed diagnostic methods could be useful for specialists employing technological plasmatrons in various sectors of the national economy such as plasma

Abstract A method for determination of the mass, of the coordinates of the center of mass, and of the tensor of body inertia was developed. The peculiarity of this method is that we have set for the body under study the rotation and finite fixed linear and angular displacements. The response of the dynamic system of the measuring bench to the changes in the location of the masses of the body and of