The article describes the design of the surface topography. The model uses experimental data on the rough surface morphology. It is a 3-dimensional surface microtopography. In case of incomplete or absent data, we can use statistically processed parameters for longitudinal and transverse surface profiles. Taking into account the possible inhomogeneity of the object of research, the microroughness of generation uses a specially developed mathematical apparatus. The simulated surface credibility. This approach makes it possible to estimate the parameters of each surface microroughness. The analysis of the simulated and real surfaces. The actual rough surface inhomogeneity causes discrepancies. It has been found that the physical processes have been carried out during the contact. It has been found that the process is to complete the process. The simulator has the highest possible reliability. It is necessary to solve a specific engineering task. This software combines a rough surface generation. It is a separate basic module modeling system.

1. http://www.iaeme.com/IJCIET/index.asp 519 editor@iaeme.com
International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 02, February 2019, pp. 519-525, Article ID: IJCIET_10_02_052
Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=10&IType=02
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication Scopus Indexed
COMPUTER SIMULATION OF THE
STRUCTURE OF TECHNICAL SURFACES AT
THE MICRO LEVEL
Sadam hamdan ahmed
Central School of Diyala, Directorate of Education Diyala, Ministry of education, IRAQ
Omar Hatem Zaidan
Department of Scholarships & Cultural Relations, University of Diyala, IRAQ
Wedyan Habeeb Hameed
Department of Computer Science, Basic Education College, University of Diyala, IRAQ.
ABSTRACT
The article describes the design of the surface topography. The model uses
experimental data on the rough surface morphology. It is a 3-dimensional surface
microtopography. In case of incomplete or absent data, we can use statistically
processed parameters for longitudinal and transverse surface profiles. Taking into
account the possible inhomogeneity of the object of research, the microroughness of
generation uses a specially developed mathematical apparatus. The simulated surface
credibility. This approach makes it possible to estimate the parameters of each
surface microroughness. The analysis of the simulated and real surfaces. The actual
rough surface inhomogeneity causes discrepancies. It has been found that the
physical processes have been carried out during the contact. It has been found that
the process is to complete the process. The simulator has the highest possible
reliability. It is necessary to solve a specific engineering task. This software combines
a rough surface generation. It is a separate basic module modeling system.
Keywords: computer simulation, rough surface, 3-dimensional model,
microroughness, surface topography.
Cite this Article: Sadam hamdan ahmed, Omar Hatem Zaidan and Wedyan Habeeb
Hameed, Computer Simulation of the Structure of Technical Surfaces at the Micro
Level, International Journal of Mechanical Engineering and Technology, 10(2),
2019, pp. 519-525.
http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=10&IType=2

2. Sadam hamdan ahmed, Omar Hatem Zaidan and Wedyan Habeeb Hameed
http://www.iaeme.com/IJCIET/index.asp 520 editor@iaeme.com
1. INTRODUCTION
Development and creation of computer models for the study of microtopography and contact
interaction of rough surfaces is an important task of modern engineering practice.
To build a 3-dimensional computer model of a rough surface, the paper [1] used a
mathematical apparatus based on the fast Fourier transform. In such a model, the definition of
the actual contact area was based on the geometric interference of two contacting models of
rough surfaces. Further, the mathematical apparatus of the model is constructed so that the
calculation of the area of actual contact and contact pressure occurs by an iterative process
with an inversion of a matrix containing discrete cells of the areas of actual contact. The
increase in the number of spots of actual contact overloaded the computational system;
therefore, in order to speed up the computational process, the authors had to simulate a
minimal fragment of interacting surfaces and an energy approach in analyzing the contact
deformations of micro-irregularities [1, 2].
The application of the theory of a random field allows obtaining the spectral
characteristics of surfaces and using them to solve the periodic problem of the theory of
elasticity with a sinusoidal stamp. Such an approach can be used to model contact
characteristics [3], however, it is limited only by elastic deformations of asperities.
Contact tasks have solutions only for bodies with the correct geometric shape, therefore,
when creating models of asperities forming technical surfaces, wedges, rods, cylinder
segments and spheres are used [4].
The development of software for computer simulation of the asperity interactions of
technical surfaces should have combined existing approaches to predicting the contact
characteristics of rough surfaces and modern computer technologies [5–7]. The synthesis of
such a model can be based on a systematic approach. To implement it at the first stage, it is
necessary to single out conditionally autonomous elements in the system. This allows you to
further add, modify and debug the modules of the program without disturbing its structure. In
relation to the problem in question, it may look like it is presented in a generalized scheme
(Fig. 1).
Input parameter values are requested sequentially at each stage of the simulation.
Modules for the synthesis of surface topography and the calculation of the characteristics of
contact interaction are necessary to carry out each of the additional elements that are used
depending on the task.
2. SURFACE TOPOGRAPHY GENERATION
Creating a model of a 3-dimensional rough surface makes it possible to bring the simulation
results as close as possible to the data obtained experimentally. When creating a model, it
should be borne in mind that for most contact interaction tasks, only a part of the layer
consisting of protrusions of a rough surface should be considered [8]. Therefore, the
modeling of a surface located below the mid-plane is omitted.

3. Computer Simulation of the Structure of Technical Surfaces at the Micro Level
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When creating a mathematical apparatus, it is assumed that each microroughness of a
rough surface is represented as equally oriented segments of ellipsoids of rotation. For
effective distribution on the plane, an algorithm has been created that takes into account the
input parameters and the overall surface structure. The heights and radii of irregularities vary
according to a random distribution law.
The model of irregularity in the form of a segment of an ellipsoid of rotation takes into
account the anisotropy of the contacting surfaces, and its particular case is the model in the
form of a spherical segment, which is widely used in contact interaction studies [9]. The
number of generated segments is sufficient for the statistical description of the simulated
rough surface. Each segment of the rotational ellipsoid that simulates microscopic roughness,
has its own geometric parameters and the coordinates of the center of the base, while the base
of the neighboring segments do not intersect. Submicrosurfaces are not counted.
Technical input parameters for modeling the microtopography of a rough surface are the
following characteristics describing each generated microroughness model:
 height;
 longitudinal and transverse radii of the top;
 longitudinal and transverse steps;
 the amount of microscopic irregularities.
These characteristics are set by the minimum and maximum values and are generated for
each irregularity according to the law of beta distribution.
The input parameters entered by the operator for computer simulation of the structure of a
discrete contact at the micro level are specific data on the characteristics of microtopography
of the contacting surfaces, and in their absence, statistically processed parameters of the
longitudinal and transverse surface profiles[1].
 Rpx, Rpy is the maximum height of the protrusion of the rough surface in the
longitudinal (x) and transverse (y) directions;
 Rax, Ray - arithmetic average deviation of the profile of a rough surface in the
longitudinal (x) and transverse (y) directions.

4. Sadam hamdan ahmed, Omar Hatem Zaidan and Wedyan Habeeb Hameed
http://www.iaeme.com/IJCIET/index.asp 522 editor@iaeme.com
 Smx, Smy - step of irregularities in the middle line in the longitudinal (x) and
transverse (y) directions;
 tmx, tmy is the relative reference length of the profile along the middle line in the
longitudinal (x) and transverse (y) directions.
Figure 2 shows the general block diagram of the surface generation algorithm. The data
entered by the operator are checked for admissibility, reducing errors due to human factors.
Next comes the cyclic generation of each microroughness, the individual values of the
parameters of the microroughness itself and the coordinates of its location on the surface
undergo additional testing with respect to the neighboring relief elements. This is necessary
to exclude situations that go beyond the model's assumption. A special adjustment algorithm
is responsible for placing the irregularities. The main tools of the algorithm are moving the
coordinates of the location of the object being processed and regulating the generated
individual parameters of the object.
This algorithm intervenes on average in 30% of cases of microscopic irregularities on the
surface, but this does not affect the reliability of the results obtained, since all corrections are
made in the permissible values of the input parameters.

5. Computer Simulation of the Structure of Technical Surfaces at the Micro Level
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3. ANALYSIS OF THE GENERATED SURFACE
Since the surface topography is the basic stage of modeling, which is responsible for all
subsequent blocks, the testing was carried out in several stages. The first stage is the study of
a simple deterministic model. The results of processing profilogram in this case can be
obtained analytically. Computer simulation of this situation showed complete agreement with
the analytical results. The second stage of testing is the simulation of real surfaces. The
microgeometry parameters of real surfaces were studied on a TR200 profilometer.
(Time Group Inc, China). As samples of the study, steel samples were used, the surfaces
of which were machined with face milling. Figure 3 shows models of rough surfaces.
Comparison with statistically processed graphs of the longitudinal and transverse reference
curves of the profiles of models of surfaces and their real prototypes was made, where tp (e)
is the relative reference length of the profile at the relative level e. For statistical processing
from models, as well as from real surfaces, five longitudinal and transverse profilograms
were taken. In the plots, triangles indicate the midpoints and confidence intervals of the
reference curves of the profiles of real surfaces, and the rectangles indicate the midpoints and
confidence intervals of the reference curves of the profiles of the models. Five longitudinal
and transverse profilograms were recorded. In the plots, triangles indicate the midpoints and
confidence intervals of the reference curves of the profiles of real surfaces, and the rectangles
indicate the midpoints and confidence intervals of the reference curves of the profiles of the
models. Five longitudinal and transverse profilograms were recorded. In the plots, triangles
indicate the midpoints and confidence intervals of the reference curves of the profiles of real
surfaces, and the rectangles indicate the midpoints and confidence intervals of the reference
curves of the profiles of the models.

6. Sadam hamdan ahmed, Omar Hatem Zaidan and Wedyan Habeeb Hameed
http://www.iaeme.com/IJCIET/index.asp 524 editor@iaeme.com
The statistically processed reference curves of the simulated profilograms have a
satisfactory agreement with the statistically processed reference curves of the profilograms of
real rough surfaces.
4. CONCLUSION
The development of such a 3-dimensional computer model of a rough surface is the basis for
building a variety of complex physical processes that occur during the contact interaction of
two surfaces. The connection of modern information technologies and developed analytical
methods allows creating a product capable of reducing the time and resource costs for testing,
designing surface treatment methods and researching the most appropriate functional
coatings.
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