SU1441246A1 - Unit for testing specimens in bending - Google Patents

Abstract

This invention relates to material testing. The purpose of the invention is to enhance the functionality by providing test samples for both static and cyclical changes in bending load and bend span. The installation contains a power frame 1 with installed

Description

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loading mechanism on it, made in the form of linkages 5, 6, one end connected to frame 1, the other with supports in the form of rollers 2, 3, two eccentrics 9, 10, kinematically connected with sliders 7, 8 with corresponding wings and driven 11 and

spring rod 12, the spring 13 of which has a variable characteristic stiffness. During operation of the actuator 11, the scenes 5, 6 make reciprocating oscillatory movements and move the supports 2, 3 along the axis of the sample 4, changing the bend span. 1 hp f-ly, 1 ill.

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The invention relates to the testing of materials, in particular to installations for testing specimens for bending.

The purpose of the invention is to expand the functionality by providing tests for both quasi-static and cyclical changes in bending force and bending span by making the loading mechanism in the form of two wings, one end of the hinge connected to the frame of the installation, and the other with the corresponding roller support, two eccentrics, kinematically connected with sliders to the wings and with the drive, and a spring-loaded stem, the spring of which has a variable stiffness characteristic.

The drawing shows the installation diagram, a general view.

Installation contains a power frame

1 and a loading mechanism mounted on it, including two supports 2 and 3 with rollers at the ends for sample 4, made in the form of two wings 5 and 6, interacting through sliders 7 and 8, eccentrically mounted on wheels 9 and 10, with a drive 11 of rotation and spring rod 12, the axis of which is located between the axles of the supports

2 and 3.

The spring 13 of the rod 12 has a variable stiffness characteristic selected from the condition of ensuring the constancy of the bending moment when the bend span is changed. I

Eccentrics, made in the form of sliders 7 and 8, interacting with wings 5 and 6 and mounted on wheels 9 and 10, are connected to the rotational drive 14 or through wheels 15 and 16

mounted coaxially to wheels 9 and 10 and associated with the latter, interacting with each other, or through wheel 17. In the depicted variant, when turning the wings at the stage of increasing the deflection, the sample moves back and forth in the direction of the axis of the shaft 12.

The same movement occurs with decreasing span. For testing at a constant bending moment, the place of fixing the wings on the frame is changed so that when turning the wings, the increase in the span is accompanied by a weakening of spring pressure in the corresponding direction of movement of the sample (down the drawing), and the decrease in the span occurs with the sample lifting (according to the drawing) and preload spring 13. The force of the spring 13 is adjusted by a screw 18, the sample

4 is placed between the plates 19.

The installation works as follows.

Dp tests in the mode of cyclic change of the bending force and the span of the bend set the spring 13 and the screw 18 bring the force on it to a predetermined level. Wheels 15 and 16 are brought into engagement with each other. Include the drive 11, the rotating wheels 15 and 16 in the opposite direction. Sliders 7 and 8 eccentrics are moved along the slit slot

5 and 6 and bring them into reciprocating motion. Rollers supports 2 and

3 is displaced reciprocally, as a result, the span of the bend of the sample changes. The characteristic of the spring is chosen so that, when cyclically moving the sample 4 in the direction of the bending load, the latter changes insignificantly. As a result, when the sample deflection changes, the bending moment also changes cyclically.

Claims (2)

1. An installation for testing specimens for bending, containing a load frame, mounted on it a loading mechanism, including two supports for the specimen with rollers at the ends, a spring-loaded rod, the axis of which is located between the axes of the supports, designed to interact with the specimen on the side opposite to the supports and kinematically associated with supports 25 drive their movement along the sample, characterized in that, in order to extend the functionality by testing the sample, not only during static bending, but also with cyclical variation of the bending load and bend span, the loading mechanism is made in the form of two wings, each the end is pivotally connected to the frame, and 35 OTHERS are fixed on the corresponding support, and, two eccentrics, kinematically connected with the sliders of the corresponding wings and the drive. 2. The installation according to claim 1, differs from 40 to the fact that, in order to increase accuracy by ensuring the constancy of the bending moment during the cyclic change of the span of the bend, di meter of the spring of the spring of the shaft is monotonously changed along its axis. statically in one direction with stops necessary for measurements. The deflection angles of the levers and the corresponding CTBeifflo span of change of the span are controlled by changing the eccentricity of the sliders. To avoid moving the specimen in the direction perpendicular to the bend direction, plates 19 (not shown). Invention Formula support end carriages are used 15 0 ABOUT 45 1. An installation for testing specimens for bending, containing a load frame, mounted on it a loading mechanism, including two supports for the specimen with rollers at the ends, a spring-loaded rod, the axis of which is located between the axes of the supports, designed to interact with the specimen on the side opposite to the supports and kinematically associated with supports 5 drive their movement along the sample, characterized in that, in order to extend the functionality by testing the sample, not only during static bending, but also with cyclical change of the bending load and the span of the bend, the loading mechanism is made in the form of two wings, each the end is pivotally connected to the frame, and 5 OTHERS are fixed on the corresponding support, and, two eccentrics, kinematically connected with the sliders of the corresponding gate and drive. 2. The installation according to claim 1, differs from the fact that, in order to increase accuracy by ensuring the constancy of the bending moment during the cyclic change of the span of the bend, di meter of the spring of the spring of the shaft is monotonously changed along its axis.