Scientific Journal of KubSAU

A more efficient use of road transport can be reached both by increasing the carrying capacity of the car and the average speed on the road. Due to limiting the safe load on the axle of the vehicle, a more promising solution is to increase the average speed on the road. Restricting car traffic speed on the roads with asphalt-concrete surface is due to the traffic safety, defined as resistance, steerabililty, vibrations of steering wheels and braking dynamics of the vehicle. The first three factors are influenced by the functional characteristics of the suspension and the state of the road surface. The share of agricultural vehicles mealage on the roads with improved surface does not exceed 65%. Nowadays, 40% of traffic volume and 9% of transport mealage are due to the transportation from the field and to the field. The aim of this work was to study the vibrational load of the load-carrying system and the driver, as well as the vehicle speed during the harvest time. To carry out theoretical research we used mathematical model "vehicle-road" system proposed by V.P. Tarasik. As a result of research we obtained the dependence of the acceleration of the front axle on the vehicle speed. The results showed that the maximum acceleration of the front axle is observed at a speed V = 20 km / h, which corresponds to external influences 1.54 Hz (9.7 rad/sec). The peak values of the vertical acceleration amounted to 5.80 m/s 2. The correctness of the mathematical model was verified by comparing the results of theoretical and experimental research in the mode of uniform motion. The experimental determination of the vibrations of the vehicle sprung mass was carried out using the sound level meter and spectrum analyzer OKTAVA-101 AM, which is equipped with a vibrational pickup AP 98. The given calculations showed that the relative error of the results of theoretical and experimental research is 3.94%, the average value of an error at a confidence coefficient of P = 0.95 is 4.76%, which confirms the correctness of the mathematical model. The studies showed that if the speed is between 14 to 40 km / h, the vibrational load on the driver is from 1.42 m/s 2 to 2.82 m/s 2, that is 2.5 ...3.5 times the sanitary standards set by the requirements of the CH 2.2.4/2.1.8.566 - 96