scholarly journals CONTACT INTERACTION OF DISCRETE-CONTINUALLY STRENGTHENED PARTS OF INTERNAL COMBUSTION ENGINES

2021 ◽  
pp. 49-59
Author(s):  
М.А. Tkachuk ◽  
S. O. Kravchenko ◽  
A. V. Grabovskiy ◽  
М.М. Tkachuk ◽  
O. V. Veretelnik ◽  
...  
Keyword(s):  
Contact Interaction ◽  
Internal Combustion Engines ◽  
Strain State ◽  
Optimization Problems ◽  
Internal Combustion ◽  
Machine Building ◽  
Combustion Engines ◽  
Stress Strain ◽  
Stress Strain State ◽  
Aluminum Part

Studies of the stress-strain state of discrete-continuously strengthening parts of internal combustion engines are described in the paper. A parametric model of a microcell containing a two-part cell has been developed. The first part simulates a fragment of an aluminum part with a surface corundum layer. The second part is a fragment of a cast iron part with a zone of discrete strengthening of steel. Vary: modulus of elasticity of the corundum layer material and the shape of the discrete hardening zone. The dependences of the strength and stiffness characteristics of the studied system on the varied parameters are established. They are the basis for substantiation of rational modes of technology of discrete-continuous strengthening of parts of internal combustion engines. In the course of research, it was found that previously determined for discrete strengthening, the effects of a favourable redistribution of contact interaction between parts are preserved for discrete-continuous strengthening. The characteristic dependences of the features of the stress-strain state of the elements of discrete-continuously strengthening parts on the varied properties of the surface layers of the continuously strengthened part, on the one hand, and the shape of the discrete strengthening zone, on the other, are determined. This makes it possible to determine the sensitivity of the characteristics to purposeful or random variation of these factors. It is also expedient to set and solve optimization problems to determine such modes of technological operation of discrete-continuous strengthening, which increase the characteristics of strength, durability, efficiency of internal combustion engines and other machines, units and assemblies containing such strengthened parts. The developed approach, models and research methods will be further applied to studies of the stress-strain state of contacting discrete-continuously strengthened parts of structures to improve the technical and tactical and technical characteristics of products of machine-building enterprises.

scholarly journals COMPUTATIONAL-EXPERIMENTAL STUDY OF CONTACT INTERACTION OF BODIES WITH NEARLY FORM SURFACES

2021 ◽  
pp. 23-32
Author(s):  
Andrey Grabovskiy ◽  
Mykola А. Tkachuk ◽  
Natalia Domina ◽  
Ganna Tkachuk ◽  
Olha Ishchenko ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Contact Interaction ◽  
Strain State ◽  
The Body ◽  
Contact Pressure Distribution ◽  
Interaction Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Flat Shape ◽  
Keywords Stress

  In many constructions, their elements are in contact with nominally matching (congruent) surfaces. In reality, this contact is disturbed due to deviations in the shape of these surfaces from the nominal. To study the effect of this perturbation on the distribution of contact pressure, the analysis of the stress-strain state of the body system of punched sheet-die is carried out. The middle element of this system deviates from the nominally flat shape. This causes a change in the contact pressure distribution. The proportionality between the clamping force and the level of contact pressure is also lost. The reliability and accuracy of the results obtained by numerical calculation have been experimentally confirmed. Keywords: stress-strain state; contact pressure; contact interaction; method of variational inequalities; Kalker variational principle; finite element method

Optimization Problems Arising from the Design of Pipes Made of Composite Materials

2020 ◽  
Vol 992 ◽  
pp. 1024-1029
Author(s):  
T. Bobyleva ◽  
A. Shamaev
Keyword(s):  
Strain State ◽  
Optimization Problems ◽  
Analytical Form ◽  
Radial Symmetry ◽  
Elastic Rod ◽  
Stress Strain ◽  
Stress Strain State ◽  
Fixed Weight ◽  
Applied Forces ◽  
Stiffness Characteristics

The work is devoted to the construction of analytical solutions for the stress-strain state of a cylindrical hollow elastic rod with a layered structure along the radius. Earlier, the problem of finding the stress-strain state of a rod of composite material fixed at one end with the applied forces and moments of forces at the other end was considered. An approximate representation of the solutions was given, which included auxiliary problems on one fragment of the cylinder, consisting of periodically repeating similar fragments. Such auxiliary problems in the general case do not have an analytical solution. In this paper it is shown that in the presence of radial symmetry of the rod section, it is possible to construct a stress-strain state in an analytical form. In addition, tensile and bending stiffness can be presented in an analytical form. The latter circumstance allows us to set a problem of optimizing the stiffness characteristics of a rod with its fixed weight. Optimization is carried out by varying the thickness of the layers of the same materials.

scholarly journals CONTACT INTERACTION OF A TORSION SHAFT WITH A SPLINED BUSH IN ELASTICALLY PLASTIC DEFORMATIONS

2021 ◽  
pp. 34-46
Author(s):  
Andrey Grabovskiy ◽  
Mykola M. Tkachuk ◽  
Anton Zavorotnii ◽  
Serhii Kutsenko S ◽  
Mariia Saverska ◽  
...  
Keyword(s):  
Contact Interaction ◽  
Strain State ◽  
Design Parameters ◽  
Stress Strain ◽  
Plastic Deformations ◽  
Suspension Systems ◽  
Stress Strain State ◽  
Manufacturing Operations ◽  
Contact Loads ◽  
Interaction Stress

Torsion shafts are the main elastic element of the suspension systems of a large number of vehicles. To simulate their reaction to the action of torque, the stress-strain state is analyzed taking into account the contact interaction with the spline sleeve. The features of the distribution of contact pressure between these bodies are established. The nature of stress concentration in the splined hollows of the shaft head is determined. Models and research methods have been developed that make it possible to develop recommendations for design decisions in the design of vehicle suspension systems. The factors are determined that ensure the strength of the torsion shaft at the values of its head diameters close to the diameters of the torsion shaft stem. In the case under consideration, this factor is firstly strength of the torsion shaft head. In particular, it was found that during manufacturing operations there are significant plastic deformations and contact loads in the heads of torsion shafts. This factor is decisive in substantiating the design parameters of torsion shafts. Keywords: torsion shaft; contact interaction; stress-strain state; elastically plastic deformation; suspension system

scholarly journals Numerical Study of Stress-Strain State of Workpiece in Contact Problem of Surface Mandrel Drilling

2021 ◽  
Vol 20 (3) ◽  
pp. 259-267
Author(s):  
N. S. Sivtsev ◽  
V. V. Tarasov
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Contact Interaction ◽  
Computational Experiment ◽  
Strain State ◽  
Numerical Study ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Stress Strain ◽  
Stress Strain State

In recent years, the economic factor has played an increasingly important role in the selection of technologies for manufacturing machine parts with specified values of normalized parameters of geometric accuracy and quality of working surfaces. As applied to surface plastic deformation processes, this is noticeably manifested in the search for effective friction control methods in the “tool – workpiece” pair, which ultimately determines the distribution pattern and the magnitude of stresses and strains in the workpiece and the tool. It is not possible to obtain a rigorous analytical solution to the problem of establishing a connection between surface conditions, friction, and the stress-strain state of the contacted bodies. In this regard, the construction of mathematical models comes to the fore, the solution of which is possible by numerical methods. The paper presents the results of a numerical study (computational experiment) of a finite-element model of workpiece deformation under various conditions of contact interaction and friction by one of the methods of surface plastic deformation – surface mandrel drilling. The friction coefficient has been chosen as the criterion for assessing the conditions of contact interaction and friction. It is shown that a change in the friction coefficient in the process of surface mandrel has no noticeable effect on the formation of a stress field in the deformable workpiece both in the axial, and in the radial and circumferential directions. At the same time, with an increase in the value of the friction coefficient in the “tool – workpiece” pair and with the associated increase in the force of mechanical resistance to deformation of the workpiece, their growth is observed. A computational experiment has confirmed the presence of non-contact deformations of the workpiece and tool during surface mandrel drilling, as well as  as a decrease in the value of residual deformations in the workpiece with a decrease in the coefficient of friction. Balance assessment of contact surface displacements in the workpiece (the inner surface of the hole to be machined) and the tool (mandrel) has shown that the deformations of the tool in the elastic region can lead to a significant decrease in the real tightness of surface mandrel drilling.

Design development, calculation of technological and strength characteristics of a flat-chamber electrobaromembrane apparatus

2021 ◽  
pp. 35-42
Author(s):  
Keyword(s):  
Structural Material ◽  
Membrane Filtration ◽  
Strain State ◽  
Machine Building ◽  
Strength Characteristics ◽  
Optimized Design ◽  
Design Development ◽  
Stress Strain ◽  
Weight Saving ◽  
Stress Strain State

The fundamentals of the development of an optimized design of a flat-chamber electrobaromembrane apparatus are considered. It is shown that the design of the structures of electromembrane devices for separating solutions of chemical and machine-building productions can be carried out taking into account the weight saving of the PA-6 structural material (caprolone) of the initial workpiece. It is noted, that for the developed design of an electrobaromembrane device for separating industrial chargetransferring solutions, a possible solution is a two-circuit solution supply scheme (sequential circulation). It is shown, that the design of the apparatus for the electrobaromembrane separation of solutions of chemical and machine-building productions is associated with finding the total area of membrane filtration. Keywords: calculation, area, separation, solution, apparatus, stress-strain state. [email protected]

scholarly journals NUMERCNAL ANALYSIS OF CONTACT INTERACTION OF BODIES WITH NEARLY FORM SURFACES

2021 ◽  
pp. 29-38
Author(s):  
Andrey Grabovskiy ◽  
Mykola А. Tkachuk ◽  
Natalia Domina ◽  
Ganna Tkachuk ◽  
Olha Ishchenko ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Interaction ◽  
Strain State ◽  
Contact Pressure Distribution ◽  
Stress Strain ◽  
Stress Strain State ◽  
Stamping Dies ◽  
The Impact ◽  
Element Method

Contact interaction of structural elements has been studied in the case of nominally close (nearly matching) surfaces. A non uniform gap is present between the contacting parts. Contact pressure and contact spot depend on the shape of this gap. Correspondingly so does the stress-strain state of the contacting bodies too. Since the problem is essentially nonlinear, the contact pressure distribution and the contact zones change with the growing loads. The solution is qualitatively different to the case of perfectly matching bodies. For the latter case, the contact pressure is linearly proportional to the load and the contact zone is predefined. Hence for the real structures for which the deviation from the nominal shape is unavoidable the impact of these inaccuracies on the contact pressure distribution and the stress-strain state need to be taken into account. This problem is addressed in the paper by example of elements of stamping dies. Keywords: element of stamping dies, stress-strain state, contact pressure, contact interaction, variational inequalities, Kalker’s variational principle, finite element method, boundary element method

scholarly journals Derivation of analytical dependencies for determining stiffness parameters of vibration isolators of vibratory machine

2020 ◽  
Vol 6 (3-4) ◽  
pp. 1-8
Author(s):  
Oleksii Lanets ◽  
◽  
Oleksandr Kachur ◽  
Vitaliy Korendiy ◽  
◽  
...  
Keyword(s):  
Computer Simulation ◽  
Large Scale ◽  
Strain State ◽  
Vibration Isolation ◽  
Solid Mechanics ◽  
Machine Building ◽  
Stress Strain ◽  
Vibration Isolators ◽  
Stress Strain State ◽  
Vibratory Equipment

Problem statement. While designing vibration isolators, the essential attention should be paid to the safety factors such as the levels of vibration and noise, as well as to the material and the structure of isolators. In major vibratory technological equipment, there are used full-metal vibration isolators, which can be designed in the form of coil (cylindrical, conical, helico-spiral) or flat (leaf-type, disc-type) springs. The problems of stress-strain analysis of metal springs used for vibration isolation of various vibratory equipment are of urgent interest among the designers and researcher. The engineering techniques of step-by-step calculation of full-metal vibration isolators of different types of vibratory technological machines are not thoroughly presented in the modern information resources. Purpose. The present paper is aimed at developing and implementing the detailed algorithm of determining the stiffness parameters of the metal coil springs used for vibration isolation of large-scale vibratory machines. Methodology. The investigations are carried out using the basic laws and principles of solid mechanics and theory of vibrations. The calculations were conducted using MathCAD software; the computer simulation of the spring’s stress-strain state was performed using SolidWorks software. Findings (results) and originality (novelty). The improved design of the vibratory conveyer-separator is considered. The engineering technique of calculating the passive vibration isolators of various vibratory equipment designed in the form of metal coil springs is developed. The proposed technique is implemented while designing the vibration isolation system of the vibratory conveyer-separator. The system’s operational characteristics are determined, and the computer simulation of the springs stress-strain state is carried out. Practical value. The proposed design of the vibratory conveyer-separator can be implemented in various industries (machine-building, chemical, pharmaceutical, food-processing, construction, mining, metallurgy, textile industries etc.) for conveying different loose, bulky and piecewise products, and separating them into fractions of different sizes. Scopes of further investigations. While carrying out further investigations, it is necessary to analyse the influence of the proposed design of vibratory conveyer-separator on the foundation during its operation, and to consider the necessary of applying the additional fixation systems.

scholarly journals Modeling the Contact Interaction of a Pair of Antagonist Teeth through Individual Protective Mouthguards of Different Geometric Configuration

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7331
Author(s):  
Anna Kamenskikh ◽  
Alex G. Kuchumov ◽  
Inessa Baradina
Keyword(s):  
Stress Intensity ◽  
Contact Interaction ◽  
Strain State ◽  
Maximum Level ◽  
Constant Thickness ◽  
Intensity Level ◽  
Stress Strain ◽  
Stress Strain State ◽  
Geometric Configurations ◽  
Wide Range

This study carried out modeling of the contact between a pair of antagonist teeth with/without individual mouthguards with different geometric configurations. Comparisons of the stress–strain state of teeth interacting through a multilayer mouthguard EVA and multilayer mouthguards with an A-silicon interlayer were performed. The influence of the intermediate layer geometry of A-silicone in a multilayer mouthguard with an A-silicon interlayer on the stress–strain state of the human dentition was considered. The teeth geometry was obtained by computed tomography data and patient dental impressions. The contact 2D problem had a constant thickness, frictional contact deformation, and large deformations in the mouthguard. The strain–stress analysis of the biomechanical model was performed by elastoplastic stress–strain theory. Four geometric configurations of the mouthguard were considered within a wide range of functional loads varied from 50 to 300 N. The stress–strain distributions in a teeth pair during contact interaction at different levels of the physiological loads were obtained. The dependences of the maximum level of stress intensity and the plastic deformation intensity were established, and the contact parameters near the occlusion zone were considered. It was found that when using a multilayer mouthguard with an A-silicone interlayer, there is a significant decrease in the stress intensity level in the hard tissues of the teeth, more than eight and four times for the teeth of the upper and lower teeth, respectively.

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