SU746203A1 - Method and apparatus for vibration displacement monitoring - Google Patents

Description

J. .

 The invention relates to measurement technology and can be used. Called to determine the vibrations of structures.

There is a known method for controlling vibration displacements, concluding that the object of research is fixed on the shaker table, the light beam is directed at an angle to the point of the surface to be tested, and the vibration effect on the object is determined by the magnitude of the deflection of the beam reflected from the object point of interest f

To do this, use a device containing a light source, a zirkgshny reflector mounted on the object under study, and photodetectors.

 The disadvantage of this method is cfi. low measurement accuracy due to unrecognizable angular deviation of the light beam.

The aim of the invention is to improve the measurement accuracy.

This goal is achieved by directing the additional beam along the normal to the test surface at the test point and determining the change in the incidence of the beam of light according to the deflection of the reflected additional beam, and calculating the value of the vibration offset X using the formula:

V - $ 2

where L is the active length of the measuring beam; X - vibration of the investigated

point-controlled surface; And - the deviation of the beam

the light reflected from the surface at an angle c is the angle of rotation of the plane / relative to the test surface at the point under study;

x is the angle of incidence of the beam on the controlled surface in this

20 point.

A device for implementing the method is characterized in that the mirror reflector is made in the form of a triangular rectangular prism, one of

25 faces of which are set aperpendicularly to the incident light beam. Fig. 1 shows a graphical rally of the instrument with a beam of 6m of measurement source, directed to the oscillating object under study and reflected from it} in Fig. 2, a device for carrying out the method.

A device for carrying out the method comprises a source of light 1, a mirror reflector 2 mounted on the object under study 3, and photodetectors 4 and 5. Mirror reflector 2 is made in the form of a triangular rectangular prism, one of the facets of which is installed perpendicular to the incident light beam, on the way of which, in front of a mirror reflector 2, a translucent mirror b is installed, and then a mirror reflector 7 is added.

The method for controlling the vibration displacements is as follows. .

The research facility is fixed on the vibrostand, the light beam 8 is directed at an angle to the point of the surface being monitored and the vibration effect on the object 3 is determined by the deflection of the beam 8 reflected from the object 3 studied. Additional beam 9 is directed normal to the controlled the surface at the studied point, determine the change in the deviation angle of the beam 8 from the light by the deviation value of the reflected additional beam 9, and the value of the vibration mix X is calculated by the formula: V.

where L is the active length of the measuring beam; X - vibration shifted

points of the controlled surface;

A is the deviation of the light beam reflected from the surface at an angle c; - the angle of rotation of the plane tangent in the studied point to the test surface; , . dL is the angle of incidence of the beam on the controlled surface at this point.

The additional beam of light is sensitive only to a change in the angle of incidence of the Ray, and according to the magnitude of the angle of deflection of the additional beam, 9

/ R /

 G - T}

gye value of the deviation of the additional beam;

 distance from the object to the plane of measurement.

Then turn on the deflection of the beam 8

equals:

. Lou

where L- is the distance from the object to the plane of measurement of the beam reflected at an angle o,

746203

and the expression for determining the magnitude of the vibration displacement will be:

;

2 sind.

J The device works as follows.

Light beams 8 and 9 are directed along the normal to the front face of mirror reflector 2. Light beam 9, reflected from the front face of mirror reflector 2, passes through the semi-transparent mirror 6 to the photodetector 4, where the deflection of the additional beam 9 is converted into an electrical signal . The beam of light 8, having passed through the mirror reflector 2. And reflected from the additional mirror reflector 7, hits the photodetector 5..

The main advantage of the invention is that in the process of control it is possible to measure the angle of incidence of a beam of light on the surface element under investigation, which improves the accuracy of control.

Claims (2)

1. A method for controlling vibration displacements, which consists in fixing the object of study on the vibration table, directing the beam of light at an angle to the point of the surface to be tested and determining the vibration effect on the object by the magnitude of the deviation ray reflected from the studied, object points, characterized in that, with the aim of increasing the measurement accuracy, an additional beam is directed along the normal to the test surface at the test point and determine the change in the angle of incidence of the light beam by the magnitude of the deflection of the reflected additional beam, and the value of the vibration displacements X is calculated by the formula:  . ,, A-btg f. Zsind where L is the active length of the measuring beam; X is the vibration displacement of the studied point of the test surface; And - the deviation of the beam of light reflected from the surface at an angle of 0;  - the angle of rotation of the plane tangent to the test surface at the studied point; (A is the angle of incidence of the beam on the controlled surface at this point. 2. A device for implementing a method for controlling vibration displacement according to Claim 1, comprising a light source, a mirror reflector fixed on the object under study, and photodetectors, characterized in that the mirror reflector is made in the form of a triangular rectangular prism, one of the faces of which is mounted perpendicular to the incident light beam. Sources of information taken into account in the examination 1. Yorish Yu.I. Measurement of vibration, M., -Mashgiz, 1956, p.302, Fig.319 (prototype).