Experimental research of an aircraft product's structure vibrations under flight loads action

Аuthors

Chukhlebov R. V.^1*, Loshkarev A. N.^1**, Sidorenko A. S.^***, Dmitriev V. G.^2****

1. Research and Production Association “BAZALT”, 32, Velyaminovskaya str., Moscow, 105318, Russia
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: ruschuhlebov@mail.ru
**e-mail: cheraken@mail.ru
***e-mail: k906@mai.ru
****e-mail: vgd2105@mail.ru

Abstract

One of the main factors affecting reliability of aircraft articles is vibration effect during the joint flight with carrier. To obtain estimates of reliability characteristics flight test of products are carried out. Modern equipment for ground vibration testing, reproducing the flight conditions, allows substantially reduce the amount of flight tests by replacing them with laboratory tests. The actual problem here is formation of laboratory tests regimes to ensure the equivalence of loading in laboratory conditions and in flight. Characteristics of vibration loads are obtained usually based on measuring data obtained during flight tests of the product or its prototype. At vibration tests, a relation is established between laboratory test modes and flight dynamic loads by the levels of vibration accelerations or stresses.

The paper presents the technique and results of flight and laboratory vibration tests on definition of vibration stresses and accelerations characteristics of an aircraft product's structure in typical flight. Laboratory tests were conducted with random dynamic loading, corresponding to loading during flight structural tests. The purpose of laboratory tests is determination of characteristics of a structure's accelerations and stresses in the conditions of a spacecraft joint flight with the carrier. This requires reproduction of conditions exhibiting adequately enough the loading condition of a product according to the basic probabilistic characteristics during typical flight.

The authors developed the technique and modes of aircraft product's vibration tests, complying with vibration loading of a product at every stage of the host aircraft flight. Using the obtained modes the tests were conducted, whereby the random dynamic loading, corresponding to the operation conditions of the product on an internal suspension bracket of the carrier, was realized. Comparison of vibration acceleration probabilistic characteristics at laboratory and flight tests demonstrated conformity of these tests' results according to root mean square values of vibration acceleration.

The developed laboratory tests technique ensures correct reproduction of random vibration loading reproduction of and aircraft product structure during the flight on an internal suspension bracket of the carrier. The technique and results of the tests can be applied for estimation the structure vibration strength of an aircraft product of various applications during the joint flight of an aircraft product with the carrier.

Keywords:

structure, aircraft product, laboratory and flight tests, random vibration, vibration acceleration, test mode

References

1. Gudkov A.I., Leshakov P.S. Metody i tekhnika letnykh ispytanii samoletov na prochnost' (Methods and techniques of aircraft flight strength tests), Moscow, Mashinostroenie, 1972, 248 p.

2. Klyachko M.D., Arnautov E.V. Letnye prochnostnye ispytaniya samoletov. Dinamicheskie nagruzki (Flight structural tests of aircraft. Dynamic loads), Moscow, Mashinostroenie, 1984, 119 p.

3. Verbitskii A. B., Rodionov G.L., Sidorenko A.S. Vestnik Moskovskogo aviatsionnogo instituta, 2012, vol. 19, no. 1, pp. 35-43.

4. Firsanov V.V. Dinamika i prochnost' ustanovok aviacionnogo vooruzheniya (Dynamics and strength of aircraft armament installations), Moscow, MAI, 2007, 400 p.

5. Metody ispytanij na stojkost' k mekhanicheskim vneshnim vozdejstvuyushchim faktoram mashin, priborov i drugih tekhnicheskih izdelij. Opredelenie dinamicheskih harakteristik konstrukcii, GOST 30630.1.1-99 (Test methods for mechanical exposure factor resistance of machines, gears and other technical products. Structure dynamic characteristics test, State Standard 30630.1.1-99), Moscow, Standarty, 2000, 19 p.

6. Metody ispytanij na stojkost' k mekhanicheskim vneshnim vozdejstvuyushchim faktoram mashin, priborov i drugih tekhnicheskih izdelij. Ispytaniya na vozdejstvie vibracii, GOST 30630.1.2-99 (Test methods for resistance to mechanical exposure factor of machines, gears and other technical products. Tests for vibration effect, State Standard 30630.1.2-99), Moscow, Standarty, 2000, 23 p.

7. Vibraciya. Terminy i opredeleniya, GOST 24346-80 (Vibration. Terms and definitions, State Standard 24346-80), Moscow, Standarty, 1980, 31 p.