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The work is devoted to improving the methods of experimental determination of internal friction parameters in materials. The aim of the laboratory experiments is to obtain physical parameters of the material that allow to take into account the damping forces in a uniaxial stress state. The research is focused on the internal friction model, which is based on the use of the generalized Prandtl model, that gives frequency-independent internal friction and allowing for the dependence of internal friction on the level of time-varying stresses. Damped oscillations during pure bending are recorded on a specially made laboratory installation. The description of the installation, the reference points of which coincide with the fixed points of the realized form of natural oscillations, is provided. The algorithm of cameral processing of experimental data is obtained. It is proposed to use a virtual system equivalent in damping. This is a system with one dynamic degree of freedom. The involvement of an imaginary system permits, after performing tests of the sample for pure bending, to acquire data corresponding to stretching - compression. The technique grants the use of long samples, which reduces the negative effect of stress concentration in the anchorages. The damping equivalent scheme makes it possible to use samples with an arbitrary cross-section. The found damping parameters for low-carbon steel are given.

The aim of the work. The work is devoted to experimental research of internal friction parameters of the material. Methods. The research of internal friction is carried out by consideration of damped oscillations of the experimental system that consist of rigid plates and a specimen in a state of pure bending. We propose to locate bearings in the fixed points to minimize energy losses in support fastenings. Fixed points are determined by using a finite element complex with consideration of free oscillations of the loose model. Results. Damping curves were determined, which demonstrate a very small logarithmic decrement of oscillations and frequency independence of inertial friction. The main result of the work is the tested improvements of the experimental technique, among which the main one is the use of fixed points for determining the places of fastening of the laboratory installation