Obtaining source functions in Fourier transform (FT) on the base of some knowing frequency distributions are presented. The proposed approach allows to study the properties of the obtained results. This technique is used for calculation of some improper integrals as well.
To establish influence of kinematic and constructive parameters of tops-harvesting machine on quality of a continuous cut of the massif of tops at oscillations in the longitudinal-vertical plane of its tops-cutting device at frontally mounted machine on a wheeled row-crop aggregate tractor. Used modeling methods based on higher mathematics, theoretical mechanics, solving a system of differential equations and compiling programs and numerical solutions on a PC. An equivalent scheme has been developed for a tops-harvester mounted on a wheeled tractor in front of it on its oscillations in the longitudinal-vertical plane, considering all the forces that arise, taking into account the kinematic excitation that occurs when moving along soil surface definitions also due to the elastic-damping properties of its support-copying wheels. For the specified equivalent scheme, on the basis of application of initial equations in the form of Lagrange of the 2nd kind, on the chosen generalized coordinates, the system of two nonlinear differential equations of oscillatory motion of the tops-harvesting machine is received. According to the analytical transformations, the solution of this system was obtained, which made it possible to obtain the f inal expressions for determining the amplitude and circular frequency of natural and forced oscillations of the tops-harvesting machine. Numerical calculations of the received expressions on the made program on the personal computer are carried out . According to the results of numerical simulation, the final expression was obtained, which allowed to determine the vertical displacements of the end of the rotary cutting unit during the oscillations of the topping machine in the longitudinal-vertical plane. Numerical calculations on the PC of the received expression gave the chance to construct graphic dependences which establish dependences of amplitude of the specified oscillations depending on constructive parameters of the tops-harvesting machine, and also characteristics of roughnesses of a soil surface and elasticdamping properties of copying wheels.
The problems of continuous motion of a cylindrical body with a displaced center of mass along vibrating horizontal and inclined surfaces are considered.
The analytical solutions of the motion equations were obtained by the method of partial discretization of nonlinear differential equations [1] and graphs of changes in the rotation angles of a cylindrical body were constructed for various cases.
The article provides an analysis of the excitation conditions and the results of the detuning of parametric resonance in mechanical drive amphibious water-jet machines. The paper substantiates the possibility of solving the problem of reducing the dynamic load on the basis of the synthesis filter low-frequency vibrations.