SU1569665A1 - Method of determining dynamic elasticity modulus of materials - Google Patents

Abstract

The invention relates to acoustic studies of materials, in particular, to methods for determining the dynamic modulus of elasticity. The purpose of the invention is to improve accuracy by using a step load. The method is implemented as follows. In the process of pressing the tip of the acoustic rod resonator, the depth of the indentation and the change in the resonant frequency are recorded. The obtained dependence ΔF (H) is approximated by a straight line, and the modulus of elasticity is determined by the formula E = N TG α, where α is the angle of inclination of the straight line, N is the coefficient obtained during calibration. 2 Il.

Description

The invention relates to acoustic studies of materials, in particular, to methods for determining the dynamic modulus of elasticity, and can be used to control the physicomechanical properties of materials when a core resonator is pressed in.

The purpose of the invention is to improve accuracy by using a stepwise increasing load.

Fig. 1-1 shows a plot of the variation of the resonant frequency as a function of the depth of indentation of the tip; figure 2 - diagram of the device that implements the method

The device contains a rod 1 with a hard tip 2, fixed at the base. Exciting 4 and receiving 5 transducers are attached to the rod attached to the rod. They are connected to a generator of 6 sinusoidal oscillations and a recording device 7, respectively. A frequency meter 80 is connected to the generator 6. The test sample 9 is mounted on the stage 10, having the possibility of reciprocating movement due to a pair of screw 11 - a nut 12. On the sample 9 there is an inductive deformation sensor 13 fixed on the base 3 and connected to the strain gauge 14 .

The method for determining the dynamic modulus of elasticity is carried out as follows.

In the rod 1 with a hard tip 2, resonant oscillations are excited with the aid of the converter 4., Vsochas-. that voltage to converter 4 is fed from generator 6. The construction of the system at the ocytvo resonance is psh using a recording device 7,

ate

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f connected to the receiving transducer 5. The frequency of the resonant oscillations is measured with a frequency meter 8. Using a screw pair screw 11 - nut 12, raise the stage 10 with sample 9 and thus press tip 2 into sample 9 to a certain depth. Depth of indentation is measured by sensor 13 strain, connected to the strain gauge 14. The oscillatory system is again tuned to resonance and the new value of the resonant frequency is measured. Calculate the change in resonance frequency fif. These operations are repeated, increasing the depth of the indentation. The dependence of the change in the resonant frequency on the depth of indentation is constructed. Af (h) 0 Approximate the obtained dependence of the direct and determine the elastic modulus of the sample material by the formula

E - n tg c6; where ОЈ is the angle of inclination to the right;

Q $ Q

five

n is the coefficient obtained

when calibrating a measuring device

Claims (1)

The method of determining the dynamic modulus of elasticity of materials, which consists in exciting resonant oscillations in a rod with a hard tip, pressing the tip of the rod into a sample of the material under test, loading the resonant frequency and indicating the specified modulus of elasticity, characterized in that In order to increase accuracy, the indentation is carried out with a stepwise increasing load, and the depth of indentation and change are recorded at each stage of the resonance frequency, and the elastic modulus was determined from the slope of straight approximating rod dependent variations of the resonance frequency of the depth of indentation. ops TsYu0, P P (nn FM1