- TITLE:
COMPREHENSIVE MODEL OF THE MICRO-HARDNESS OF DIAMOND BURNISHED 41CR4 STEEL SPECIMENS
- AUTHOR(S):
V. P. Dunchev
- ABSTRACT:
Diamond burnishing (DB), based on severe plastic deformation of the surface layer, improves
the surface integrity (SI) of metal components and thus, enhances their operating properties. The
micro-hardness is one of the mechanical characteristics of the SI. The increased micro-hardness due
to DB is a precondition for improved wear and fatigue crack resistance of the treated component.
The article presents a comprehensive experimental mathematical model which predicts the micro-
hardness distribution in depth from the surface depending on the diamond insert radius and
burnishing force. The selection of the significant governing factors is based on previous study. The
experimental model is based on a fourth-order one-dimensional polynomial whose variable is the
depth and the coefficients are functions of the two governing factors
- PAGES:
25-
- TITLE:
FINITE ELEMENT SIMULATIONS OF STATIC MECHANICAL SURFACE TREATMENT PROCESSES - A REVIEW AND PROSPECTS
- AUTHOR(S):
V. P. Dunchev, M. D. Ichkova
- ABSTRACT:
This article reviews finite element (FE) simulations of static mechanical surface treatment (MST)
processes for metal components. These static burnishing methods, based on severe plastic
deformations of the surface and subsurface layers, improve the surface integrity (SI) of the respective
components dramatically and thus their operational properties. The finite element method (FEM) is
a basic method used for numerical investigations of MST processes. Although FEM always requires
experimental verification and an experiment to establish an adequate material constitutive model,
this method saves the researcher significant time and resources. In this article, a comprehensive
analysis of the published studies devoted to FE simulations of static MST processes has been
conducted. Based on the analysis, five basic conditions have being established in order to build an
adequate FE model of the static burnishing process
- PAGES:
14-
- TITLE:
MATHEMATICAL MODELING OF WORKING PROCESSES IN A LIQUID-MAGNETIC DAMPER
- AUTHOR(S):
I.V. Nochnichenko*, O.S. Haletskyi, D.V. Kostiuk, S.V. Strutynskyi
- ABSTRACT:
A mathematical model of the workflow has been developed, which made it possible to study the
influence of design and geometric parameters, and also the influence of the working fluid
temperature on the performance of a hybrid liquid-magnetic damper. The combination of an
innovative hybrid structure, magnetic field and hydraulic throttling in the damper gives it new
properties, however, during development, arises the problem of choosing rational parameters of its
elements to ensure a given operating characteristic. To solve the problem posed, we analyzed the
physical processes occurring during the operation of the damper and built a mathematical model
using a cyclic-modular approach. Based on the results of mathematical modeling, a prototype of a
liquid-magnetic damper was made.
- PAGES:
91-
- TITLE:
MATHEMATICAL MODELING OF DYNAMIC PROCESSES OF THE TERRESTRIAL ROBOTIC COMPLEX MANIPULATOR
- AUTHOR(S):
S. Strutynskyi, R. Semenchuk
- ABSTRACT:
The calculation scheme, that allow to investigate dynamic processes of the manipulator of the
terrestrial robotic complex is offered. The dependences describing dynamics of the manipulator are
received. A dynamic model of the manipulator has been developed. This model takes into account the
possibility of using controlled damping devices. The obtained results take into account the influence
of variable external factors on the dynamic processes of the ground-based robotic complex. The
mathematical model of the manipulator can be combined with the existing mathematical model of the
chassis. The proposed mathematical model has practical value and can be used in the development
of a mechatronic system for stabilizing the position of the manipulator of the terrestrial robotic
complex.
- PAGES:
9-
- TITLE:
INTENSIFICATION OF TRANSFER PHENOMENA IN TECHNOLOGICAL PROCESSES DUE TO THE USE OF CAVITATION IMPACT
- AUTHOR(S):
I. Nochnichenko, O. Jakhno, K.Lugovska
- ABSTRACT:
The article deals with the cavitation process from the perspective of the transfer phenomenon.
For the first time, an attempt was made to link two physical processes - cavitation and the transfer
phenomenon. As a result, new opportunities open up for the intensification of working processes in
cavitation devices and, as a consequence, the possibility of deep control of the operating
characteristic of the system. It is shown that taking into account the transfer phenomena and
accompanying processes depends on the state of the liquid and is determined by the transfer
coefficients (viscosity, density, pressure). The processes in the cavitation apparatus of the
hydrodynamic type are experimentally investigated, the mechanism of intensification is proposed, the
regularities of mass transfer in liquid media under conditions of hydrodynamic cavitation are
studied. The influence of ultrasonic cavitation on the process of electrolysis of a liquid medium has
been investigated. The comparison of the obtained results of visualization with experimental
dependences is carried out
- PAGES:
8-
