Recently, articulated buses with a capacity of 150-200 people have been increasingly used in passenger transportation. The overall length of such buses is limited to 18.5 meters. It is explained by the need to meet regulatory requirements for maneuverability.
Understanding the mechanics of a turbulent boundary layer is important, since in most practical problems it is the turbulent boundary layer that is primarily responsible for the surface shear force or surface resistance. The velocity distribution in a turbulent boundary layer on a flat plate is considered parallel to the flow. It is important to know the correlations between the boundary layer thickness and shear stress. Therefore, the problem of controlling the flow in a boundary layer on a flat plate is one of the important problems of boundary layer mechanics.
A mathematical model has been developed to study the amplitude-frequency characteristics of the resonator beam. Nonlinear mechanics methods were used in the modeling process. The model takes into account the influence of changes in the elastic properties of the beam material on its oscillation amplitude and frequency. To analyze the internal processes in the material, Voigt's and Bolotin's laws were applied.
The methodology of research of the influence of the degree of loading, kinematic parameters of movement, and nonlinear power characteristics of elastic elements and shock-absorbers of the suspension system on their steerability on curved sections of the road is developed. The research is based on the equation of kinetostatics of the system of sprung-unsprung part and differential equations that relate the motion of the sprung part of vehicles. Concerning the last, they take into account both loading of a vehicle and nonlinear-elastic characteristics of shock-absorbers.
Problem statement. While designing vibration isolators, the essential attention should be paid to the safety factors such as the levels of vibration and noise, as well as to the material and the structure of isolators. In major vibratory technological equipment, there are used full-metal vibration isolators, which can be designed in the form of coil (cylindrical, conical, helico-spiral) or flat (leaf-type, disc-type) springs.
Dynamic model for research of object transportation location influence on its vibrating loading by moving through a number of single obstacles, road with random microprofile and rough road is offered. Differential equations and methods of their integration in MATLAB Simulink software product are presented. The values of frequencies and amplitudes of vertical oscillations, vibration acceleration of the transportation object at different locations in the vehicle body were obtained.
The main malfunctions that arise when operating a vehicle in Ukraine are the failure of the suspension elements and vehicle tires due to the poor condition of the most roads [11]. The car suspension elements soften the dynamic loads and smooth out the oscillations from the unevenness on the road while riding and provide a good stability and smoothness of the car ride.
The article substantiates the possibility of further improvement of highly effective interreonance oscillatory systems. To do this, it is proposed to apply a discrete-continuum oscillation system in which a third ultra-light mass is used as a body with distributed parameters (ultra-light weight).
The calculation diagrams of oscillating systems and operation features of vibratory finishing machines are considered. The mathematical models of three-mass and four-mass oscillating systems are presented. The amplitude values of the oscillating masses displacements are derived. The functions of inertial and stiffness parameters optimization are formed. The optimization problems are solved with a help of MathCAD software.
The problem of substantiation of operational efficiency of vibratory separators designed on the basis of vibratory hopper feeders with electromagnetic vibrations exciters and with conic working bowls is considered in the article. The complex of factors influencing the accuracy and productiveness of separation of coins and disk-shaped products on two or more fractions is overviewed. New models of structures for the effective solution of separation problems are proposed.