SU1483309A1 - Resonator for vibration test bed - Google Patents

Abstract

This invention relates to a technique for vibration testing of articles. The aim of the invention is to enhance the operational capabilities of the resonator by creating signed impulses. The resonator comprises a beam 1 of rectangular cross section with hinged supports 2 and 3, of which support 3 is made hingedly movable. With these supports, the beam is installed on the table 4 shakers. The resonator is also equipped with a plate 6, which serves to fasten the product in the plane of oscillations elastically curved in the plane of oscillation, the ends of which are attached to the ends of the beam 1. The natural oscillation frequency of the plate lies in the preresonant frequency range of the beam. When resonant bending oscillations of the beam, axial movement of the hinge-movable support 3 of the beam occurs and deformation of the plate 6 bonded to it occurs. As a result, a series of sign-constant load impulses of increased amplitude are applied to the test article mounted on plate 6. 2 Il.

Description

1

The invention relates to a technique for vibration testing of articles, namely, resonators mounted on a table of a vibration test bench to obtain an increased load level.

The purpose of the invention is to expand the operational capabilities of the resonator by creating signed impulses.

FIG. 1 shows a resonator for a vibration test bench; in fig. 2 - plate and beam oscillation shapes.

The resonator contains a beam 1 of rectangular cross-section with symmetrically arranged at its ends hinge supports 2 and 3 in the form of semi-cylinders oriented across beam 1. Semi-cylinders are used for mounting and fixing beam 1 on table 4 of a vibration test stand (not shown). The beam is fastened on the table with bolts 5. A fixture with a test product (not shown) is installed in the middle of a plate 6 elastically bent in the plane of oscillation, the ends of which are attached to the ends of beam 1 with bolts 7. A sleeve 8 placed with a small gap in the rectangular slot 9, serves as a guide for axial displacement of beam 1. Support 3 is made hinged-movable (height of sleeve 8 is greater than height of beam 1).

To eliminate the imposition of resonant oscillations of beam 1 with the frequency of foi and plate 6 with the frequency of foe, the following condition must be met, i.e. the intrinsic frequency of plate 6 lies in the preresonant frequency range of beam 1. When plate 6 is deformed and its amplitude is small, it increases the thickness and rigidity of the plate 6. In addition, to prevent distortion of the oscillation shape, it is advisable to limit the mass of the tested product, taking it 2-3 times less than the mass of the plate 6. Otherwise, the inertial force caused by the action of the mass and here, will additionally deform the plate 6.

The resonator works as follows.

The vibration effect produced by the vibration test bench excites resonant bending vibrations 10 of beam 1, at which the axial

moving the pivotally movable support 3 of the beam 1 and deforming the plate 6 bonded to it, as a result of which a series of sign-shaped impulses of increased amplitude 11 are applied to the test product mounted on the plate 6. Regardless of the direction of bending of the beam (up-down), the plate deformation will increase in comparison with the initial one by decreasing the length of its span with periodic axial displacement of the hinged-movable beam support. Thus, at the extreme upper and lower positions of the middle part of the beam, the middle of the elastically curved plate will occupy only the extreme upper position.

The application of the proposed resonator allows to expand the operational capabilities, since it is possible to carry out a series of signed impulses of load on the product if it is attached to

plate or periodic alternating loading of the product in case of its fixation on the beam.

Claims (1)

Invention Formula 0 A resonator for a vibration test stand containing a rectangular beam with hinged supports symmetrically located at its ends for mounting and securing the beam on the stand table 5 for testing a product, characterized in that, in order to enhance operational capabilities by creating sign-impulses it is equipped with a plate that is elastic in the plane of oscillations and is attached to the ends of the beam; the ends of which are attached to the ends of the beam, the plate’s own frequency lies in the preresonance region frequency of the beam, and one of the supports of the beam is hinged-movable. // 2