Influence of variable weight of liquid cargo on dynamic loading of the running system of transported units
Abstract
The constant increase in agricultural production forces farmers to use both automobile and tractor machinery in transport work. Therefore, creating new tractor equipment, manufacturers are trying to meet performance.
In the study of transport work used in the agro-industrial complex, there is a problem with the movement of a wheeled tractor with trailer and / or semi-trailer tanks, which are partially filled with liquid. As there are no internal partitions in tractor tanks, then the transportation of a tank partially filled with liquid cargo will lead to significant free oscillations. This trend, together with the regular increase in transport speed leads to longitudinal and transverse instability, increases both energy costs and emergencies (there is an impact on smoothness, handling and stability of the vehicle, increasing the dynamic load of the chassis, etc.).
The aim of the work is to study the dynamic load of the running system of the trailer and semi-trailer tank when performing transport work with a wheeled tractor. To solve this goal it is necessary to: assess the dynamic load of the running system of units (tractor tanks) when performing transport work with a wheeled tractor; to carry out the analysis of influence of constructive indicators of a suspension bracket of the semi-trailer tank for the purpose of reduction of dynamic loading of a running system of a wheeled tractor. In solving this goal, a technique was used that provided mathematical modeling of the longitudinal movement of a wheeled tractor with tanks of different filling volumes. The model used takes into account the redistribution of liquid in the tank, which is caused by oscillations of the shell, using the characteristics of surface Rayleigh waves. The analysis of the dynamic load of the running system of tractor tanks was based on the determination of the force generated by the pneumatic tires of the wheels.
As a result, the data of the theoretical research reflecting influence of redistribution of liquid in semi-trailer tanks on an indicator of dynamic loading of a running system of tanks are received. It is also established that to reduce the amplitude of the dynamic load of the running system of the semi-trailer tank, it is advisable to introduce damping elements (shock absorbers) into the structure. When selecting the elastic characteristics of the suspension of a semi-trailer tank, it is necessary to conduct a comprehensive study to determine the dynamic load on the running system, because incorrect selection of the stiffness of the suspension can lead to a resonant zone of dynamic load in the range of transport speeds.
