scholarly journals Integral criterion of the state of physical parameters of the surface layer of machine parts

2021 ◽  
Vol 1061 (1) ◽  
pp. 012040
Author(s):  
A V Totay ◽  
M N Nagorkin
Keyword(s):  
Surface Layer ◽  
The State ◽  
Physical Parameters ◽  
Integral Criterion ◽  
Machine Parts

scholarly journals Influence of reinforcing plastic surface deformation on surface performance of machine parts

2019 ◽  
pp. 7-14
Author(s):  
Z. М. Оdosii ◽  
V. Ya. Shymanskyi ◽  
B. V. Pindra
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Residual Stresses ◽  
Surface Deformation ◽  
Fatigue Cracks ◽  
Surface Plastic Deformation ◽  
Original Structure ◽  
Physical Parameters ◽  
Surface Plastic ◽  
Machine Parts

The performance of the machines part reinforcement using surface plastic deformation shall be considered as formation of the whole complex of surface parameters and quality and their impact on the operational properties of these parts. The main surface quality parameters, affecting the performance of machine parts are geometric (microgeometry, wavelength, roughness, shape of inequalities, the size of the supporting surface, the direction of the traces of processing); physical parameters (structure, degree and slander depth, residual stresses in the surface layer). In the machine building, many methods of superficial plastic deformation are used for part reinforcement; these methods essentially differ in the scheme of impact of the surface deforming part to be treated. After analyzing the results obtained by scientists, involved in research on surface plastic deformation of surface layers and surfaces of parts, it was found that after hardening, practically all structural changes contribute to reinforcement of the surface layer material and increase the plastic deformation resistance. Increasing the density of dislocations and the separation of carbides, which block the shear slides and create obstacles to the movement of dislocations. Due to these changes, resistance to formation and spread of fatigue cracks have increased. The treatment depth, magnitude of residual stresses and increase in hardness depends on the original structure and chemical composition of the material. Reinforcement regimes have significant effects on the wear resistance. Use  of diamond smoothing, vibration processing, combined methods (surface plastic deformation in combination with other reinforcement methods, as well as the use of a combined tool) opens up new possibilities for increasing the quality characteristics of the surface and the surface layer of parts, and accordingly, increasing their operational properties with all the diversity and complexity of used processes. Based on the results of the studies, practical recommendations on the application of methods of hardening by surface plastic deformation of machine parts and a methodology for designing technological processes for their manufacture considering manufacturing capabilities are proposed.

Theoretical justifi cation for use of combined methods for hardening of surfaces of machine parts in order to control their fretting resistance

2020 ◽  
pp. 339-342
Author(s):  
V.F. Bez’yazychny ◽  
M.V. Timofeev ◽  
R.V. Lyubimov ◽  
E.V. Kiselev
Keyword(s):  
Surface Layer ◽  
Fatigue Limit ◽  
Surface Hardening ◽  
Theoretical Justification ◽  
Hardening Process ◽  
Subsequent Application ◽  
Machine Parts ◽  
Combined Methods

The theoretical justification for the hardening process of the surface layer of machine parts for combined methods of surface hardening with subsequent application of strengthening coatings, as well as reducing or increasing the fatigue limit due to the fretting process is presented.

Effect of diamond burnishing parameters on the state of the processed surface layer of billets made of high-strength "30ХГСН2А-ВД" steel

2020 ◽  
pp. 82-86
Author(s):  
A.N. Shvetsov ◽  
D.L. Skuratov
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Strain Hardening ◽  
Processing Speed ◽  
Synthetic Diamond ◽  
High Strength ◽  
The State ◽  
Diamond Burnishing

The influence of the burnishing force, tool radius, processing speed and feed on the distribution of circumferential and axial residual strses, microhardness and the depth of strain hardening in the surface layer when pr ssing of "30ХГСН2А-ВД" steel with synthetic diamond "ACB-1" is considered. Empirical dependencies determining these parameters are given. Keywords diamond burnishing, strain hardening depth, circumferential residual stresses, axial residual stresses, microhardness. [email protected], [email protected]

Identification of Physical Helicopter Models Using Subspace Identification

2020 ◽  
Vol 65 (2) ◽  
pp. 1-14
Author(s):  
Sevil Avcıoğlu ◽  
Ali Türker Kutay ◽  
Kemal Leblebicioğlu
Keyword(s):  
Parameter Estimation ◽  
State Space ◽  
Nonlinear Optimization ◽  
Physical Parameter ◽  
Test Data ◽  
Flight Test ◽  
The State ◽  
Physical Parameters ◽  
Subspace Identification ◽  
Study Results

Subspace identification is a powerful tool due to its well-understood techniques based on linear algebra (orthogonal projections and intersections of subspaces) and numerical methods like singular value decomposition. However, the state space model matrices, which are obtained from conventional subspace identification algorithms, are not necessarily associated with the physical states. This can be an important deficiency when physical parameter estimation is essential. This holds for the area of helicopter flight dynamics, where physical parameter estimation is mainly conducted for mathematical model improvement, aerodynamic parameter validation, and flight controller tuning. The main objective of this study is to obtain helicopter physical parameters from subspace identification results. To achieve this objective, the subspace identification algorithm is implemented for a multirole combat helicopter using both FLIGHTLAB simulation and real flight-test data. After obtaining state space matrices via subspace identification, constrained nonlinear optimization methodologies are utilized for extracting the physical parameters. The state space matrices are transformed into equivalent physical forms via the "sequential quadratic programming" nonlinear optimization algorithm. The required objective function is generated by summing the square of similarity transformation equations. The constraints are selected with physical insight. Many runs are conducted for randomly selected initial conditions. It can be concluded that all of the significant parameters can be obtained with a high level of accuracy for the data obtained from the linear model. This strongly supports the idea behind this study. Results for the data obtained from the nonlinear model are also evaluated to be satisfactory in the light of statistical error analysis. Results for the real flight-test data are also evaluated to be good for the helicopter modes that are properly excited in the flight tests.

Effect of the State of a Surface Layer on the Properties of Pd–P Catalysts in the Hydrogenation of Alkylanthraquinones

2019 ◽  
Vol 60 (6) ◽  
pp. 808-817 ◽  
Author(s):  
L. B. Belykh ◽  
T. P. Sterenchuk ◽  
N. I. Skripov ◽  
V. V. Akimov ◽  
V. L. Tauson ◽  
...  
Keyword(s):  
Surface Layer ◽  
The State

scholarly journals VI. The effect of hydrogen on the discharge of negative electricity from hot platinum

1908 ◽  
Vol 208 (427-440) ◽  
pp. 247-273 ◽  
Keyword(s):  
Surface Layer ◽  
The State ◽  
Great Length ◽  
Series Of Experiments ◽  
The Wire

The effect of hydrogen on the discharge of negative electricity from hot platinum was examined by the writer in 1903 (‘Phil. Trans.,’ A, 352, vol. 202, 1903); it was found to produce a very large increase in the current carried by the discharge. At pressures below 0·1 millim. of mercury the leak was found to increase with the pressure and to fall when the pressure was reduced. The experiments in the paper just referred to were all done with nearly new platinum wires which had not been heated in the gas for any great length of time, because it was known that long continued heating caused the wire to disintegrate, its surface becoming covered with a network of cracks. The present paper contains an account of a series of experiments in which wires were heated for long periods in hydrogen, so that any gradual changes in the effect of the hydrogen could be observed. It appears that continued heating in hydrogen alters the character of the effects observed, so that the behaviour of an old wire may be very different from that of a new one. In the previous paper I suggested that the effect of hydrogen was due to the presence of hydrogen in the surface layer of the platinum, and this view appeared to be supported by the facts. Professor O. W. Richardson (‘Phil. Trans.,’ A, 413, vol. 207, 1906) puts forward a different theory, viz., that the hydrogen alters the state of the platinum, so that the effect may remain even after the removal of all the hydrogen.

Presentation of Assembly Condition and Subassembly Function Using Two Force Feedback Displays

2000 ◽  
Vol 12 (1) ◽  
pp. 2-10
Author(s):  
Ryoko Furusawa ◽  
◽  
Kazuaki Tanaka ◽  
Norihiro Abe ◽  
Katsuya Matsunaga ◽  
...  
Keyword(s):  
Force Feedback ◽  
Virtual Work ◽  
Daily Life ◽  
Reaction Force ◽  
The State ◽  
Work Space ◽  
Machine Parts ◽  
Haptic Sensation

Assembling is one of the important factors in our daily life. The aim of assembling is to obtain a particular function from the subassembly which is generated by putting some parts together. This fact shows that assembling machine parts is possibily the most appropriate example to exeute. If we assemble some machine parts, we decide the positions by their shapes, and then, make sure both the state of parts by reaction force fed back to the hand when a part touches other parts and the behavior of the subassembly. In addition, it is advisable to use both hands for assembly. In this research, we constructed a virtual work space using a force display which gives us haptic sensation returned from not only assembling operation but collaboration with both hands.

scholarly journals Structural Stiffness Identification Based on the Extended Kalman Filter Research

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Fenggang Wang ◽  
Xianzhang Ling ◽  
Xun Xu ◽  
Feng Zhang
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
State Equation ◽  
The State ◽  
Physical Parameters ◽  
Structural Stiffness ◽  
Structural Dynamic ◽  
Discrete State ◽  
Response Acquisition ◽  
Shear Structure

For the response acquisition of the structure section measuring points, the method of identifying the structural stiffness parameters is developed by using the extended Kalman filter. The state equation of structural system parameter is a nonlinear equation. Dispersing the structural dynamic equation by using Newmark-βmethod, the state transition matrix of discrete state equation is deduced and the solution of discrete state equation is simplified. The numerical simulation shows that the error of structural recognition doesnot exceed 5% when the noise level is 3%. It meets the requirements of the error limit of the engineering structure, which indicates that the derivation described in this paper has the robustness for the structural stiffness recognition. Shear structure parameter identification examples illustrate its applicability, and the method can also be used to identify physical parameters of large structure.

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