Identification of the dynamic characteristics of the technological machining system

Abstract

The method of experimental determination of the dynamic characteristics of the technological machining system, taking into account the generalized structural scheme of the process, is presented. An equivalent elastic system under the influence of a force disturbance can be represented as a one-mass model with two or three degrees of freedom. The mathematical model should contain three main parameters: frequency of natural oscillations, stiffness and damping coefficient of oscillations, which are determined experimentally. An example of identification for the end milling operation on the 6M13 vertical milling machine is presented. The created stand contains a multi-component MCS10-005-3C sensor, ClipX BM40 signal amplifiers and a computer with a special interface and allows you to determine stiffness based on the results of "load-displacement" measurements. To determine the frequency of self-oscillations, a signal in the form of an impulse response is used from a special PCD Piezotronics Impact Hammer connected to a storage oscilloscope. During the experiment, a file is created in Excel format, which is presented in the form of an amplitude-frequency characteristic using standard Fourier transforms. The obtained spectrum is approximated by the typical amplitude-frequency characteristic of the oscillating link, from which the frequency of natural oscillations is determined.