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2
Egamov J.J. Magistrant Prof. Shukurov R. U. Tashkent Institute of design construction and maintenance
of automobile roads VIBRATION ANALYSIS OF ROAD CONSTRUCTION MACHINES Annotation: In this article, different values of vibration impacts on road building machines have been analyzed in static and dynamic regimes
Key words: Tilt, frequency of vibration, comfort level, suspension systems, Schematic model.
The bulk of the vibrations in the road-building machines are vibrations that
occur on uneven roads. To prevent this, the road construction machine will do the oscillation. In
order to be comfortable with the worker, it is necessary to identify and know the limits of the vibration limits of road construction machinery. Because the vertical vibration frequency of the road construction machines is not normal, for example, if the vibration of the road " Актив construction machines is slowed down, first, it
пассив система
скстема affects machine stability and management
deteriorates, and second, the road construction machine quickly fires the driver.
For example, the average quadratic value of the excavator vibration impact on the seat was determined by theoretical and experimental methods using three types of suspension systems (passive, half active and active). [1].
The average squared value of the vibration wheel placed on the carriageway is determined by the following formula.
= Щ (1)
qlz- vibration to the seat;
4sz -vibration transmitted from the machine floor;
The following formula was used to determine the fluctuations of the system: Stz = max(qlz(t) -(qsz(t)) min(qlz(t) -(qsz(t)) (2)
The vibration values of the rear axle: [2].
Table 1.
seat type unwanted signal The mass of the driver 55 kg The mass of the driver 98 kg
Theoretical Experience Theoretical Experience
TFEz Stz .MM TFEz Stz.MM TFEz Stz.MM TFEz Stz.MM
Passive construction EM3 0.891 83 0.953 79 0.783 102 0.852 96
EM5 0.547 48 0.585 47 0.472 54 0.496 60
EM6 0.576 8 0.579 9 0.432 10 0.447 11
half active EM3 0.787 80 0.795 79 0.659 81 0.693 77
EM5 0.498 46 0.492 49 0.406 44 0.401 48
EM6 0.505 14 0.555 16 0.399 12 0.406 14
active EM3 0.444 77 0.481 81 0.465 80 0.515 85
EM5 0.332 40 0.329 42 0.381 47 0.349 43
EM6 0.384 12 0.356 14 0.322 15 0.366 16
The vertical movement equation that is formed on the road surface of the road construction machine and the wheel axis is as follows.
m2 ' X2 + k2 ( X2 " X) + C0 X2 = 0
mx ■ X1 -c0X2 + k1Xj + (xj -x2)k2 = cq + kxq
(3)
(4)
Here, the weight of the wheel axis of ml and m2 and the weight of the wheel axis, kl and k2 - the tire and the rescue; c0 - amperage resistor coefficient; c is the overclocking coefficient; xl and x2 - vibration of wheel and wheel axis and q -positioning of the road profile.
The following experimental links are used for the standardized view of the road surface velocity model, ie the frequency spectrum and its spectral density function:
M
Sn = b Q" |3Mj (5)
Here ^ - frequency profile, b and n the coefficients accepted for the road.
LLntH-i npynatHacrt
maiiiHHa x£-ïi-a;âjnmiiT
noma opi^ajm
Picture 2. Schematic model of the excavator at moving time
Picture 3.
Quadrangle model of excavator
Using the Laplace Transformation Principle (3) and (4) we obtain the following equation:
Z2(s) _ (c0s + k2)(cs + kl)
H =
H 2 =
Zi(s)
Z0(s) (m2s2 + c0 s + k2)[mjs2 + (c + c0)s + (kj + k2)] (m2s2 + c0s + k2)(cs + kj)
(6)
Z0(s) (m2s + c0s + k2)[mis + (c + c0)s + (k1 + k2)] - (c0s - k2) (7) Here Laplace Transformations of Z2 (s), Z1 (s) and Z0 (s) -x1 (t), x2 (t) and q (t) Variables; HI and H2 transmission functions.
10 1 o
Ghastotia [Qs]
Picture 4. quadrant transmission function graph
Ghaslota [Gs]
Picture 5. vibration velocity and migration graph of the raster Typically, when calculating vehicle accuracy, the stimulator pulses in the path profile can be taken as impulse power (I), ie the unit of measure [N / Hz ], its
N2/
spectral density unit [ 'Hz ]. Its mathematical expression is as follows:
1 r
I _ mv _f Fdt v _-J Fdt
J or mJ
Here is F _ czr + kzr the road power, zr the pathway profile Through experimental research, the accelerometer measurements of the vertical motion of the car body and the resulting number of results can be generated by the transfer function of the computer, using the Fourier Transform, and the body's spectral density function.
Literature:
1. Sekulic. D, Dedovic. V, Mladenovic. D. "General oscillatory model of vehicles for passenger transport". Conference: International Conference on Traffic and Transport Engineering-belgrade, November 27-28, 2014
2. Nahvi H. "evoluation of whole body vibration and ride comfort in passenger car", International Journal of Acoustic and Vibration, vol.14 No. 3, 2009.
