RU2335748C1 - Method of high-intensity shock testing of devices and equipment - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method consists in shock loading of tested object using pyrotechnic devices with preset shock acceleration spectra followed by acceleration recording in control points. Originally pyrotechnic devices are exploded in immediate proximity from attachment point, thus shock is transferred to tested object only through air environment. Then accelerations generated by air shock waves are recorded, and shock acceleration spectra from air shock waves are received in control points. Thereafter tested object is connected to pyrotechnic device and shock loading is applied. Then shock acceleration spectra are received in control points generated by net effect of strain wave and air shock waves. Net effect shock acceleration spectra are isolated from air shock waves spectra. It allows for conclusion as to size of shock acceleration spectrum generated by strain waves propagating along the tested object.

EFFECT: possibility of objective estimation of tested object loading and improvement of testing and following analysis of measurement results.

7 dwg

Description

This invention relates to impact test methods and can be used in tests for high-impact impacts of various instruments and equipment.

There are quite a lot of shock testing methods using vibrating electrodynamic stands, stands with falling tables, etc. At present, the most widely used are testing methods for the shock spectrum of accelerations, when the effect itself is not important, but the reaction that this effect causes in the construction is important (book 2, “Testing Technique”, book 1, Moscow: Mechanical Engineering, 1982 , p. 334-335).

The closest is the test method according to the patent of Russian Federation No. 2262679. The method of impact tests of high intensity instruments and equipment by the method of impact spectra, which consists in the impact loading of systems with pyrotechnic devices with a predetermined shock spectrum of accelerations and the distance from the pyrotechnic device to the tested devices and equipment. The recorded impact spectrum of accelerations from one pyrotechnic device is not less than the required one, and then it is carried out by adjusting the number and installation locations of pyrotechnic devices - adopted as a prototype.

The disadvantages of this method include the fact that when using explosive pyrotechnic devices (for example, explosive bolts), the effects of shock waves transmitted through air are not controlled, whereas in real conditions, the destruction of pyrotechnic devices occurs either at supersonic speeds of the rockets, or outside atmosphere. It should also be noted that some accelerometers have a fairly high sensitivity to the effects on their body. Those. accelerometers located close to the source of the shock may give a false signal.

The task to be solved by the claimed invention is directed is the elimination of these drawbacks, which will allow higher quality impact testing of high intensity impacts.

The solution to this problem is achieved by first blasting the pyrotechnic devices in the immediate vicinity of their attachment points, while the transmission of shock to the test object occurs only through the air, and the accelerations created by air shock waves are recorded, and shock spectra are obtained at the control points accelerations from air shock waves, then a pyrotechnic device is attached to the test object and shock loading is carried out, after which they are obtained in the control Kah spectra shock accelerations from total deformation impact waves and shock waves of air further from the drum acceleration spectra total impact shock spectra exclude air from shock waves and inferring the magnitude spectrum of the shock acceleration of deformation waves propagated by the test object.

The essence of the claimed solution is illustrated by drawings, in which Fig. 1 shows a general diagram for conducting impact tests, Fig. 2 is a cross-section of the mounting region of a pyrotechnic device, Fig. 3 is a test diagram allowing impact loading of a test object only through air, Fig. .4 - section in the area of fastening the pyrodevice to the technological trolley, in Fig.5 - the total USD from the combined action of the waves, in Fig.6 - the USU from the air shock wave, and in Fig.7 from the total USU were excluded components of the USU from the air shock wave. The stand for impact tests consists of a burst bolt 1, a cushioning rod 2, an antenna with a set of radio engineering blocks 3, cords 4, on which a honeycomb panel 5 is hung, control sensors (accelerometers) 6, an adapter 7, an embedded 8, inserts for a burst bolt 9 , technological trolley 10. According to this scheme, typical impact tests are carried out.

In FIGS. 3-4, the cushioning rods 2 with bursting bolts 1 and adapters 7, inserts 9 are disconnected from the honeycomb panel (from the mortgage 8) and installed on the technological trolley 10 with a minimum clearance (~ 30 mm). The installation locations of the burst bolts are located under their mounting points on the honeycomb panel.

The essence of the decision can be explained as follows. When conducting shock tests using separable pyrotechnic devices, when the test object is subjected, in addition to the action of the deformation wave, to shock effects transmitted through the air, this component must be taken into account. Providing a gap between the pyrotechnic device and the test object during impact testing, the transmission of the deformation wave to the test object is excluded. It is clear that this should be the smallest possible gap, otherwise it will be necessary to take into account the propagation velocity of the shock wave in air, its scattering (pressure reduction), etc. All registered components will be determined only by shock loads transmitted through the air. Accelerometers will record accelerations and from them are built shock spectra of accelerations (USU). In this case, even a false signal issued by the accelerometer can be taken into account in the formation of loading modes. Then, the standard fixing of the pyrotechnic device is made and its operation. Obviously, such a signal recorded by accelerometers contains both components from the deformation wave and from the shock wave transmitted through the air, as well as distortions in the readings caused by the air shock wave when it acts on the accelerometer bodies. Accordingly, and the USU from such exposure contain all these components. Further from the total USU are deducted USU from an air shock wave. Adding / subtracting the USD is not a usual procedure due to the nonlinearity of the USU, but this technology belongs to the “know-how” of the invention and is not considered in this application.

The exclusion of shock components caused by an air shock wave allows one to obtain an objective assessment of the loading of the test object, to improve the quality of the tests and the subsequent analysis of the measurement results.

Practical example

Figure 1-4 shows a test scheme of the equipment of one of the subsystems of the repeater of the spacecraft "Express AM". In the process of testing (figure 1, 2) were recorded levels of impacts at the control points 6 and received for them USU (figure 5). Then, the cushioning rods were docked with the technological trolley in the places of their docking with the honeycomb panel 5 at a distance of ~ 30 mm from the panel (Figs. 3, 4). Next, the operation of the explosive bolts was carried out and shock spectra of accelerations from the air wave were obtained at the control points 6 (Fig.6). Then, using special mathematical support, the components of the control system from an air shock wave were excluded from the total control system. In Fig.7 shows a graph of the USU with the excluded component from the shock wave.

As can be seen from the graph, the components of the air shock wave have a noticeable effect on the total USD in the frequency range up to 1000 Hz.

Of the sources of information and patent materials known to the authors, the totality of features similar to the totality of features of the claimed objects is not known.

Claims (1)

The method of impact tests of high intensity instruments and equipment by the method of impact spectra, which consists in the impact loading of the test object with pyrotechnic devices with predetermined impact acceleration spectra, and registration of accelerations at control points, characterized in that the pyrotechnic devices are first blown up in close proximity to their attachment points, while the transmission of shock to the test object occurs only through the air, and the acceleration created by air shock waves at the control points receive the shock spectra of the accelerations from the air shock waves, then a pyrotechnic device is attached to the test object and shock loading is carried out, after which the shock acceleration spectra from the total influence of the deformation waves and air shock waves are obtained at the control points , then from the shock spectra of the accelerations of the total impact exclude the shock spectra from air shock waves and make a conclusion about the magnitude of the shock spectrum deformation from deformation waves propagated through the test object.

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