RU1796893C - Impulse holographic plant - Google Patents

Abstract

The invention relates to the study of the dynamic stress-strain state of structures and structures by the method of photoelasticity. The purpose of the invention is to increase research productivity by obtaining a hologram for three points in time with one pulse exposure to the object from one exposure. The installation includes a four-pulse light source and three optical shutters in the reference beams, after each of which one expander is installed. The optical shutters are controlled via a diode isolation circuit with a synchronizing device coupled to a pulsed light source and device. PTO Dynamic impact on the object. After the specified time delays, the photographic plate is exposed. After developing and fixing it, a hologram of wave processes is obtained for three given time points, 2 ill. ate with

Description

The invention relates to the field of studying the dynamic stress-strain state of structures and structures by the photoelastic method.

, A well-known cinema system based on the use of delay light lines is known. The unit is designed for high-speed registration of fast-flowing processes with an interval between. There are about 40 frames per frame and cannot be used to record processes within 10-500 microseconds. In addition, the installation is difficult to set up and requires large areas for installing an optical delay line (up to 20 m in length).

A multi-frame holographic system for registering fast processes is known, based on the principle of the formation of a dynamic reference beam using the FABRI-PERO interferometer. whose base is being changed by changing. pulse values

voltage applied to the piezoceramic base of one of the mirrors. The installation has several drawbacks, the main of which are the inadequacy of the restored image to the fixed object and the complexity of the creation. a multi-pulse step voltage acting on the piezoelectric interferometer FABRI-L ÖPO.

The closest is a dual-pulse holographic setup for investigating fast processes. It contains two monopulse light sources connected by a synchronizing device, a polarizing light and two conventional beam splitters, optical elements for forming an object beam and two reference beams directed to a photographic plate (FP).

A disadvantage of the known installation is the low accuracy and productivity due to the impossibility of obtaining holograms

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for three or more instants of time with one pulsed impact on the object, and also the high cost of installation due to the use of two pulsed source Coves of light.

The aim of the invention is to increase the accuracy and productivity of the installation by obtaining holograms for three

, moments in a single exposure and

one impulse effect on the object and

reduction of its cost due to reductions

the number of expensive impulse sources. Cove of Light .. ..:,. ; ; -:. ;: - at .. .- .- / ... ::

The specified goal is achieved by the fact that in

impulse topographic installation

. dl. A dynamic study containing a pulsed light source polarizing and conventional beam splitters, optical elements, a photographic plate and a block

: synchronization is additionally established after the beam splitter — in the reference beam, two translucent and one ordinary mirror, after each of which, in front of the expanders, Pockels cells with nd-rodamn are installed, moreover, Pockels cells are connected through diodes and a synchronizing device with an optical shutter of a many-1mpuyr light source ;; .. In Fig-i 2 shows the proposed

installation,.; - -. . ; : .-- L .-- -. . .,: ..: -. .

. In Fig. 2, a block diagram of a mm-holographic holographic installation for investigating the dynamic stress-strain state of structures and structures by photoelasticity is shown.

The setup contains a four-pulse source of light 1, an itel light detector and 2, a collimator 3, an object under investigation 4, a photographic plate 5, a mirror 6, and optical optics. creations, including Prkkels's cell and poloid 7, 8, 9, TO expanders, synchronization unit 11, diode isolation 12, and a device for dynamically acting

investigated object 13Installation works as follows ..- / ZOM ... . . - ..:

The first exposure of the photographic plate 5 is produced by the first light pulse of vertical polarization from the source: light t, excited by a pulse from the synchronization unit 11, simultaneously with the pulse being supplied through the dynamic action device 13 to the object of study 4.

 In this case, part of the light beam through beam splitters 2, mirror 6, optical shutters 7, 8 9 and expanders .10 as three. Reference beams of vertical polarization

 also arrive at photoplate S. In this case, simultaneously with the first light pulse of the light source and the dyne pulse

A control pulse is applied to the optical shutters 7, 8, 9, 5. Thus, the first exposure of the photographic plate 5 is carried out simultaneously with the dynamic exposure to the object 4, when the wave has just begun to move to the study area.

0 After a predetermined delay time from the block, and the Synchronization, a control pulse arrives at the light source 1 and through 12 N decoupling, and the optical shutter 7, carried out the second exposure of the photographic plate 5, when wave5 has already entered the studied area of the object. After a given delay time comes.

- gives the third pulse to the Light source 1 from the synchronization unit and through the diode isolation 12 it enters the optical shutter b, 0 performs the third exposure of the input module 5 and, with the arrival of the fourth pulse from the synchronization unit 11, after the time of the on-hold: light source 1 and through the diode isolation 12 to the optical shutter 9 is carried out. 5 a fourth exposure of photoparietin is taken. 5 .- / L -...-; .; .; ::: ..; ;.-.-; .... ... . ...; As a result, on the photopasteage after V manifestation and fixing, we obtain the holopiaMMbi wave processes for three given time instants. ; .; ;. :; ..,.:.; The experimental investigation of the claimed pulsed topographic installation showed that the accuracy

 stress studies in the object increased 5. by obtaining holograms for

three points in time by 15% compared with the prototype, productivity in

three times, and the installation cost was reduced by 3%.

0; ...: ...;.;, /: - :; -;.; - ...

Claims (1)

SUMMARY OF THE INVENTION A pulsed holographic apparatus for dynamic research, comprising a pulsed light source located along the radiation, a beam splitter, an object holder and a photographic plate mounted along one of the separated light beams, a mirror and a beam expander installed along the other from the separated light beams, and a synchronization unit, which requires that, in order to increase the research productivity, it is equipped with two translucent mirrors arranged in series along 55 along the radiation path between the beam splitter and the mirror with three Additional beam expanders installed along the beams reflected respectively from the first and second translucent mirrors, with three optical shutters placed 51796893 6 along the radiation between the corresponding roloid, whose inputs are electrically mirrors and beam expanders and are called up with the synchronization unit, and the source filled in the form of a Pokhels cell and in the light is made four-pulse. FIG. f & e / 9. 2 , 45.