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UDC - 631.372:621.0:62-214.2
STUDY OF DEFORMATION OF THE FRAME OF MTZ 82 TRACTOR
VARDAN ALEXAN VARDANYAN
Candidate of Technical Sciences, Associate Professor, Armenian National Agrarian University,
Armenia, Yerevan
ANDRANIK SAMVEL HAKOBYAN
Assistant lecturer, Shushi University of Technology, Armenia, Stepanakert
HENRIK VARDAN VARDANYAN
Candidate of Technical Sciences, Associate Professor, Armenian National Agrarian University,
Armenia, Yerevan
Abstract
Equations of static-dynamic loads have been obtained for the assessment of the strain-deformation condition of the semi-frame of MTZ-82 tractor. Calculations were performed for four modes of tractor operation with the help of these equations and rational schemes of tip elements with various complexities (simplified, basic and adjusted). In order to study the deformation condition of the tractor frame and its elements, this approach is designed to quaillatively and quantitatively assess their strength and rigidity.
By assessing the deformation state of the frame with different load modes and calculation schemes, the areas with the heaviest and the lightest load of the frame were identified during those modes.
Key words: semi-frame, method of tip elements, state of deformation, loading equations, differential equations, node transfer, matrix of roughness,
Introduction
As many researches show, sufficiently accurate results of theoretical study of strain-deformation condition of difficult spatious structures were obtained in case of calculation by Method of Tip Elements (MTE) [1, p.23]. As a result we will use description of MTE for theoretical research of semi frame of the tractor studied by us which will enable to totally mechanize the process of formation and solution of differential equation systems.
Conflict setting
MTZ tractors being exploited in rough mountainous conditions need to be estimated by their strain-deformation condition.
The aim of our research is to theoretically estimate the strain-deformation condition of semi frame of MTZ tractor by three stated schemes and to reveal more overloaded zones. Methods and materials
The static-dynamic equations of the frame were obtained for the solution of the task set [1,
p.23].
The balance equation of the structure is
[k fe}=M+(4 ( i)
Where {q}-is the vector of transfer nodes
[K]-is matrix of stiffness
[K] = fv[B]T[G][B]dv
V (2) Where [G]-is the matrix of elasticity of the given material [B] matrix was obtained from near [O] matrix T-is the coefficient of rearrangement {P}-is the analogue loads on the nodes
{P}=$M {q)dv + J[<*f {p)ds (3)
Jv Js
Where v and s are the volume and surface of the studied element, R-is the matrix of centralized forces.
The general matrix of the structure stiffness is
(4)
IIM
[K ]=£a' [K ¡A*
Where Ae-is buleva matrix (everly line which has only one element shows that the node belongs to element e or not), MN- is number of elements. It is admitted that ¿ [k]e-is built in that coordinate system where [k]- is built, i.e. global coordinate system.
The matrix of stiffness of the element in global system is
e=1
[K J = [K f A, (5)
Where [K°]-is the matrix of stiffness of the element in local coordinate system, X-is guiding co-sinus matrix between local-global coordinate system.
The static (1) and dynamic (5) equations of TE are apt to be realized via applied programs and systems which enable to practically solve every task of construction mechanics [1, p.23]. One of such systems is widely known ANS YS system.
The studies will be conducted in the following loading regimes (Table 1) [3. p.24].
Table 1
The loading regimes of the tractor frame
N /n Loads Regime parameters Loading KN
N Change limits
1 Tillage Horizontal force Rx 0...30
Vertical force Py 0...15
Side force Rz 0.8
2 Loader Semi-frame force Fmass 0.12
Anti weight mass Ghk 0.9.5
3 Truck transportation activity Trucking force on the hook Fe 0.30
4 Trucking farm machine, movement over the furrows Weight of farming machine G 0...20
Semi- frame rolling force Rh 0...67
In order to study the strain-deformation condition of the frame of the tractor, three calculation schemes such as simplified, basic and adjusted were developed [2, p.84-91].
Although in the first calculation scheme the approximations and assumptions are numerous and the calculation error is bigger, nevertheless, in this case in a very short period of time (about 5 minutes) a preliminary assessment of the tractor frame is made and the more overloaded zones are revealed (Pic.1).
attachment Gear- backside
As can be seen from Pic. 1, the areas of connection of gearboxes, technological hatches and holes are more loaded.
The calculations for the quantitative assessment of the stiffness of the tractor frame and its elements were performed by basic and adjusted calculation schemes. Since the mentioned zones have different numbers as tip elements in the basic and adjusted schemes, it is expedient to conditionally enumerate these zones (Pic.2).
4~\ ri 1
о с □ (¿Ту r-H \ ж
—г • * 0 » • I
3 I GIO ФФ WO 2> ®t40© 730 ' D
H3Q 2900
-<
_
Pic. 2 Semi- frame scheme in more overloaded zones
Calculation values are given in Table 2 and four regimes of loading are given in Table 1
Table 2. Calculation values
Zone Transfer 10-3 *5
Basic calculation scheme Adjusted calculation scheme
Variants of loads
1 2 3 4 1 2 3 4
1 1,46 2,18 1.08 0.66 2.05 2.33 1.012 0.66
2 3,05 3,45 1.57 0.88 2.99 3.4 1.51 0.9
3 1,89 2,33 0.92 0.65 1.89 2.31 1.06 0.53
4 1,67 2,1 0.89 0.66 1.62 1.98 0.86 0.57
5 0,23 - - - 0.24 - - -
6 0,33 - - - 0.35 - - -
7 0,22 - - - 0.21 - - -
8 3,58 3.86 1.74 1.09 3.54 3.86 1.74 1.1
9 3,41 3.91 1.85 1.12 3.48 4.03 1.33 1.16
10 0,75 1.21 0.09 0.18 0.72 1.19 0.09 0.2
11 0,36 - - - 0.35 - - -
12 1.65 1.8 0.35 0.43 1.63 1.88 0.32 0.45
Deformation analysis of the frame makes it possible to identify its most loaded and less rigid
areas.
As can be seen from the data presented, the following zones are subjected to greater deformation (Table 2).
In the second zone in case of basic calculation scheme we have 3.45*10-3 m, and in case of adjusted scheme -3.4*10-3m.
In the fourth zone in case of basic calculation scheme we have 2.1*10-3m, and in case of adjusted scheme - 1.98*10-3m.
In the eighth zone we have 3.86*10-3 m in both cases.
In the ninth zone we correspondingly have 3.91*10-3 m and 4.03*10"3 m.
In the twelfth zone we correspondingly have 1.8*10-3m and 1.88*10"3m.
It should be noted that the 2nd and 4th zones coincide with the gearbox from the coupling ball part to the decelerating gearbox, the 8th zone with the divider box under the gearbox connection belt, the 9th zone with the zone of joining holes under the middle and secondary shaft supports and the 12th zone with the hole zone under the half-axis supports.
In general, we can say that the chosen method provides results with a high degree of accuracy with its calculation schemes.
Conclusion
1. For the study of the deformation condition of the tractor frame and its elements, rational schemes of tip elements of various complexities (simplified, basic and adjusted) are developed aimed at quantitative and qualitative evaluation of their strength and stiffness.
2.The analysis of the calculation results showed that the scheme of each developed tip element has its limits, which provides acceptable accuracy of the calculation.
3. The areas with the more loaded and less loaded zones of the frame were identified by assessing the deformation state of the frame with different load modes and calculation schemes.
REFERENCES
1. Vardanyan, V.A. Evaluation of dynamic loads of automobile frames and indicators of reliability/Abstract of requiring the degree of Candidate of Technical Sciences, Yerevan//-2008. -23 p.
2. Vardanyan, V.A. Hakobyan, A.S. Calculating schemes of the frame of MTZ 82 tractor/ Bulletin of High Technology 4(18)/Shushi University of Technology, Shushi//-2021.- p. 84-91
3. Zuzov, V.N. Development of methods for creating load-bearing systems of wheeled vehicles with
optimal parameters/ Abstract of requiring the degree of Candidate of Technical Sciences/ -2002.24 p.
