ON ONE OF THE METHODS OF VIBRODIAGNOSTICS BY THE VECTOR OF PHASE COORDINATES OF A LINEAR SYSTEM

The issue of precision rotor systems regarding the relationship between their dissipative characteristics and changes in design parameters has been investigated. A dynamic model has been identified. The influence of parameter changes on the properties of the system has been studied and analyzed analytically. The sensitivity matrixand interparametric sensitivity have been determined. An analysis of the method of assessing changes in design parameters of a precision rotor system based on the deviation of the components of the phase coordinate vector has been carried out. Solving technological problems to ensure high quality of machines and devices, stability of their operating characteristics and vibration resistance during operation requires conducting research that is no less important than research related to the development of principles of operation, design and selection of parameters. One of the most promising areas for ensuring high performance and reliability of machines and devices is the development of methods of technical diagnostics. The application of the vibration diagnostics method is based on the presence of correlation dependencies of the dynamic characteristics of the entire assembly on the contact pressure in the connection due to a change in the stiffness of the joints. Changing the stiffness of individual elements leads to a change in the reduced stiffness of the assembly, and at the same time, the dynamic characteristics of the artificially created vibration field characteristic of it: frequencies and amplitudes of resonant oscillations, damping indicators, impedance and phase relations. Comparative analysis of these experimental data suggests the possibility of developing a method for assessing the technical condition of fixed contact joints of precision systems by changing their dynamic characteristics. The purpose of the article. The need to study and analyze the impact of parameter changes on the properties of the system analytically, that is, using a known mathematical model of the system. To solve the problem, the most acceptable methods are sensitivity theory. Sensitivity matrices allow us to determine the parameters that are sensitive and invariant to the state vector. This information answers the question of which parameters most determine the vibrational pattern of the object. In addition, determining the sensitivity matrix will allow us to significantly simplify the dynamic model of the system, leaving only those parameters that most determine the vibrational state of the system. In real objects, the mathematical model of which is determined by a system of linear differential equations, the connection of oscillations in different coordinates is characterized by the relationship of parameters. We will determine the parameters of the system, the change of which does not affect other parameters, but significantly affects the state vector of the system, the elements of which can be the values of vibration displacement, vibration velocity and vibration acceleration. We will solve the problem based on the joint consideration of two matrices: the sensitivity of the object and the interparametric sensitivity. Thus, for vibration diagnostics, the method of assessing changes in the design parameters of a precision rotor system by the deviation of the components of the phase coordinate vector (vibrational acceleration, velocity or vibration displacement amplitudes) will be the most obvious. Indeed, any, as small as possible, changes in the design elastic-inertial parameters of the system will necessarily be reflected in its amplitude-frequency characteristic. The effectiveness will depend on the accuracy of measurement of the components of the phase coordinate vector and on the absolute value of the sensitivity of their changes to changes in the design parameters. There is another side to the problem in setting the problem of vibration diagnostics of contact connections in precision instrument making. Determining the diagnosis of the conformity of the design quality should be carried out using a diagnostic system, which means the appropriate information and hardware support in solving this problem. To increase the accuracy and eliminate measurement errors, it is necessary to ensure full automation of the processes of vibration loads, vibration measurement of dynamic characteristics, efficiency and reliability of information and measuring systems. In this case, the most preferred are self-oscillating, including phase-resonant methods of perturbing mechanical vibrations. The use of microcomputer complexes will allow for express analysis to assess the quality of assembly of precision rotor systems directly in production conditions.