scholarly journals SUBSTANTIATION OF DESIGN DECISIONS OF ELEMENTS OF MILITARY OBJECTS IN CONDITIONS OF CONTACT AND PLASTIC DEFORMATION

2021 ◽  
pp. 97-103
Author(s):  
Mykola M. Tkachuk ◽  
Mariia Saverska ◽  
Andrey Grabovskiy ◽  
Serhii Kutsenko
Keyword(s):  
Plastic Deformation ◽  
Contact Interaction ◽  
Strain State ◽  
Variational Principles ◽  
Physical Nonlinearity ◽  
Parametric Modeling ◽  
Stress Strain ◽  
Military Equipment ◽  
Stress Strain State ◽  
Design Solutions

New design solutions, technologies and materials are required to improve tactical and technical characteristics of military equipment. Often this implies operation in such conditions as contact interaction and elasto-plastic deformations of materials. New models and research methods are developed for better utilization of modern materials and improved performance of military equipment. They account directly for complex physical and structural nonlinearities. The properties of conventional and novel materials are determined both in bulk and on surfaces at microstructural level. This will enable physically adequate and mathematically correct analysis of stress-strain state. The new advanced design solutions will emerge through the objective-driven search by means of parametric modeling. The project will extend traditional local problem statements with newly developed variational principles that account for structural and physical nonlinearity and are suitable for parameterization. This will create the basis for fundamental analysis of torsion bar suspensions, hydrovolumetric and gear drives and other crucial components of combat vehicles, engineering solutions for domestic manufacturers of military equipment that will bring their tactical and technical characteristics to highest modern standards. Keywords: contact interaction; stress-strain state; intermediate layer; contact pressure; contact area; plastic deformation

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.

scholarly journals Stress strain state of elastic plate with elliptical cut-out

2020 ◽  
pp. 3-8
Author(s):  
E.E. Deryugin ◽  
Keyword(s):  
Plastic Deformation ◽  
Stress Concentration ◽  
Driving Force ◽  
Strain State ◽  
Mechanical State ◽  
Concentration Coefficient ◽  
Stress Strain ◽  
Crack Driving Force ◽  
Stress Strain State ◽  
Stress Concentration Coefficient

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.

Effect of Stress-Strain State during Combined Deformation on Microstructure Evolution of High Carbon Steel Wire

2016 ◽  
Vol 870 ◽  
pp. 460-465 ◽  
Author(s):  
Alexandr Gulin ◽  
Marina Polyakova ◽  
Eduard Golubchik
Keyword(s):  
Plastic Deformation ◽  
Carbon Steel ◽  
Cross Section ◽  
Strain State ◽  
Steel Wire ◽  
High Carbon Steel ◽  
Grain Structure ◽  
Basic Operation ◽  
Stress Strain ◽  
Stress Strain State

It is shown that new methods of severe plastic deformation design require combining different methods of plastic deformation. As for carbon steel wire, using drawing as a basic operation is obvious. The combination of drawing with bending and twisting was estimated by the stress-strain uniformity complex. It allows choosing the deformation processing conditions which ensure the uniform stress-strain state in each point of the carbon steel wire cross section. Based on such combination, a new method for manufacturing of semi-products with ultra fine grain structure by drawing with torsion was developed. The combination of wire drawing in two consecutively arranged dies with simultaneous bending and torsion allows achieving complex stress-strain state of the processed metal and ensure the share stresses. Metallographic investigation shows that such scheme of combined plastic deformation provides the uniformity of metal microstructure in its cross section.

scholarly journals Consideration of the loading of the traffic lines in the design of automobile roads

2021 ◽  
Vol 274 ◽  
pp. 02009
Author(s):  
Denis Nikolenko ◽  
Maxim Nikolenko ◽  
Anastasiya Filippova
Keyword(s):  
Traffic Flow ◽  
Strain State ◽  
Dynamic Deformation ◽  
Uneven Distribution ◽  
Stress Strain ◽  
Stress Strain State ◽  
Freight Traffic ◽  
Design Solutions ◽  
The Difference ◽  
Strength And Durability

The article focuses on the importance of the strength and durability of highways due to the projected increase in freight traffic. It also describes the consequences of uneven distribution of loads in traffic lanes, depending on the prevailing traffic in each lane. The studies, that were carried out earlier by various scientists, were taken into account, thankfully to which results were obtained on the composition of the traffic flow, the difference in the loading of road pavements, as well as the stress-strain state of road structures. As a result, a model that reflects the dependence of the influence of the speed of movement of vehicles on the dynamic deformation of structures, was developed. Consequently, a number of design solutions were established to ensure the required strength of all structures.

scholarly journals Assessment of stress-strain state in cylindrical parts after transverse running with flat plates

2017 ◽  
Vol 2 (5) ◽  
pp. 38-43 ◽  
Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
Дак Фам ◽  
Dac Pham
Keyword(s):  
Plastic Deformation ◽  
Strain State ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Flat Plates ◽  
Stress Strain ◽  
Program Complex ◽  
Vertical Loading ◽  
Stress Strain State ◽  
Cylindrical Parts

For the deformation strengthening of parts like axles, pins, and bushes there is offered a method of surface plastic deformation based on blank rolling with flat plates. The method allows machining parts which do not have center holes. At transverse running a blank bending affected by transverse loading forces is excluded. With the aid of ANSYS program complex there is considered a change of a stress-strain state in cylindrical parts at transverse running. There are defined plastic and elastic cylinder deformations after loading. The distribution of residual stresses along cylinder section in the plane of vertical loading is obtained. The stress state of samples run with flat plates on equivalent stress is assessed. An efficient value of running at transverse running used as a basic parameter of surface plastic deformation is defined.

scholarly journals THEORETICAL BASIСS OF PROVIDING THE TECHNICAL CHARACTERISTICS OF MILITARY AND CIVIL VEHICLES BY JUSTIFICATION OF THE FORM AND PROPERTIES OF THE MATERIALS OF CONTACTING ELEMENTS

2021 ◽  
pp. 17-22
Author(s):  
Andrey Grabovskiy ◽  
Iryna Hrechka ◽  
Mykola M. Tkachuk ◽  
Mariia Saverska ◽  
Serhii Kutsenko ◽  
...  
Keyword(s):  
Strain State ◽  
Variational Principles ◽  
Technological Factor ◽  
Interaction Strength ◽  
Structural Elements ◽  
Stress Strain ◽  
Strength Criteria ◽  
Stress Strain State ◽  
Contact Loads ◽  
World Class

Elements of constructions of modern military and civil vehicles usually work in conditions of high contact loads. Аt the stage of their creation, strength studies are carried out using traditional models of contact of bodies of nominal shape. Нowever, the real structural elements have deviations from such models, which are due to design and technological factors: macrodeviation of the shape, surface roughness, strengthening etc. Such perturbations of nominal parameters have a significant effect on the distribution of contact pressure between the elements of military and civil vehicles, however, traditional methods for studying the stress-strain state of contacting bodies do not make it possible to take such factors into account fully, collectively and exhaustively. To eliminate the existing contradiction, a semi-analytical method is proposed, which is based on the development of variational principles and boundary-element sampling. The created models make it possible to take into account the regularities of the influence of shape perturbations and properties of the surface layers of contacting bodies on the stress-strain state. As a result, it becomes possible to justify favorable perturbations by strength criteria. Such models and methods are offered to the work, and on their basis it’s proposed the implementation of research elements of military and civil vehicles for appointment to ensure world class the technical and tactically technical characteristics. Ключові слова: military and civilian vehicles; design and technological factor; stress-strain state; contact interaction; strength

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

scholarly journals MATHEMATICAL MODELING OF STRESS-STRAIN STATE OF COMPOSITES REINFORCED WITH DISCRETE FIBERS IN TENSION AND COMPRESSION, TAKING INTO ACCOUNT PHYSICAL NONLINEARITY

2016 ◽  
Vol 38 (06) ◽  
pp. 124-130
Author(s):  
Andrei Mastislavovich Korneev ◽  
◽  
Olga Petrovna Buzina ◽  
Andrei Vladimirovich Sukhanov ◽  
Ilya Andreevich Shipulin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Strain State ◽  
Physical Nonlinearity ◽  
Stress Strain ◽  
Stress Strain State ◽  
Tension And Compression

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

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