Multilayer composite material structure impact on the aircraft structure stiffness characteristics degradation

Aeronautical and Space-Rocket Engineering


Аuthors

Akulin P. V.*, Gavrilov G. A.**

PJSC UAC Sukhoi Design Bureau, 23A, Polikarpova str., Moscow, 125284, Russia

*e-mail: plus-orange@yandex.ru
**e-mail: gg1986@mail.ru

Abstract

Layered composite materials (CM) are of a wide application range in the design of aircraft. These materials advantage consists in the ability of changing the package physical characteristics by the reinforcement angle varying. Physical properties degradation under various types of loading [1-4], which, in its turn, affects the aircraft strength, should be accounted for while the aircraft structures design.

The presented article studies characteristics degradation of a composite material of different structure. The hypothesis that transversal cracks leading to the physical characteristic degrading and residual deformation appearance, occur in the composite material monolayer while loading is accepted. The issue of the transversal cracks occurrence in the matrix structure of a composite material is being considered on a wide scale in [1-18].

The article considers the samples from a woven organoplastic and unidirectional prepreg of carbon fiber- reinforced plastic, with various stowing of 0 – 90 and 0 – 90 – ±45 degrees, as well as with various geometric characteristics.

The article presents the results of the experiment on composite panels cantilever bending under normal climatic conditions. The samples were loaded by the forced displacements of the stop along the mounting axis with a step of 2 mm, in the direction of the profile. Unloading and measurement of residual deformations of the uttermost edge were performed after each loading step.

Stiffness characteristics degradation of the material is being determined in this article by residual deformations measuring after the sample loading. A more accurate method of cracking detection in the CM matrix structure is non-destructive testing with roentgenography methods application. The said method will allow detecting cracks in the CM structure with normalized accuracy. The issue of non-destructive defects testing in composite materials is being considered in [19-20].

The full-scale tests allowed establishing the presence of residual deformations in structurally similar flexible elements of all types of cross-section. It was revealed that the stiffness properties degradation in the composite material occurs at the cantilever bending of the sample.

Structurally, such flexible elements with reinforcement angles of 0 – 90 – ±45 display the smallest increase in residual deformations, compared to the samples, which reinforcement angle corresponds to 0.90 degrees. It is associated with the fact that organoplastics are of a braided structure, and at reinforcement angles of 0 – 90 degrees half of the fibers are not beingincluded in the overall bending of the structure. The reinforcement angle of 0 – 90 – ±45 degrees herewith allows including all the fibers of woven organoplastics in the general bend and reduce the package stiffness characteristics, which, in the aggregate, leads to the stresses drop in the monolayer of the composite material package and, as the result, the least progression of stiffness characteristics degradation.

Keywords:

properties degradation in composite materials, damages accumulation in the composite material matrix, layered composites, transversal cracking in the composite material matrix

References

  1. Reifsnaider K. Vypusk 44. Prikladnaya mekhanika kompozitov. Sbornik statei 1986-1988, Moscow, Mir, 1989, 357 p.

  2. Krivorodov V.S., Leksovskii A.M. Mekhanika kompozitnykh materialov, 1987, no. 6, pp. 999-1006.

  3. Highsmith A.L., Reifsnider K.L. Stiffness-Reduction Mechanisms in Composite Laminates. In: Reifsnider K.L. (ed.) Damage in Composite materials: Basic mechanisms, accumulation, tolerance, and characterization (A83-14551 03-24), Philadelphia, PA, American Society for Testing and Materials, 1982, pp. 103-117. DOI: 10.1520/STP34323S

  4. Johnson W.S. Mechanisms of fatigue damage in boron/ aluminium composites. Technical Memorandum NASA- TM-81926 19810007619, 1980, 60 p.

  5. Luat D.C., Lurie S.A., Dudchenko A.A. Modeling of degradation of the composite properties on cracking and delamination when subjected to static and cycling loading. Composites: Mechanics, Computations, Applications: An International Journal, 2010, vol. 1, no. 4, pp. 315-331. DOI: 10.1615/CompMechComputApplIntJ.v1.i4.20

  6. Dudchenko A.A., Lur’e S.A. Modelirovanie protsessov rosta povrezhdennosti i degradatsii mekhanicheskikh svoistv sloistykh kompozitov (Modeling of the processes of damage growth and degradation of mechanical properties of layered composites), Мoscow, MAI, 2019, pp. 60-61.

  7. Dudchenko A.A., Lurie S.A., Halim K. Multiscale modeling on damage mechanics of laminated composite materials. CDCM 2006 – Conference on Damage in Composite Materials (18-19 September 2006; Stuttgart, Germany), pp. 23-26

  8. Vanin G.A. Mikromekhanika kompozitsionnykh materialov (Micromechanics of composite materials), Kiev, Naukova dumka, 1985, 302 p.

  9. Malmeister A.K., Tamuzh V.P., Teters G.A. Soprotivlenie polimernykh i kompozitnykh materialov (Resistance of polymer and composite materials), 3rd ed., Riga, Zinatne, 1980, 571 p.

  10. Volkov S.D., Stavrov V.P. Statisticheskaya mekhanika kompozitnykh materialov (Statistical mechanics of composite materials), Minsk, BGU, 1978, 206 p.

  11. Lurie S.A. On the entropy damage accumulation model of composite materials. Process of workshop on computer synthesis structure and properties of advanced composites. Russia-US, Institute of Applied Mechanics; 1994, рр. 6-18.

  12. Kanaun S.K., Chudnovskii A.I. Mekhanika tverdogo tela, 1970, no. 3, pp. 185-186.

  13. Kiyalbaev D.A., Chudnovskii A.I. Prikladnaya mekhanika i tekhnicheskaya fizika, 1970, no. 3, pp. 105-110.

  14. Soborejo A.B.O. Use of entropy principles in estimating reliability functions for creep rupture characteristics of engineering materials al high temperatures. International Conference on the Strength of Metals and Alloys (4-8 September 1967; Tokyo), pp. 252-256.

  15. Movchan A.A. Mekhanika tverdogo tela, 1990, no. 3, pp. 115-123.

  16. Movchan A.A. Problema prochnosti tonkostennykh konstruktsii (The problem of strength of thin-walled structures), Moscow, MAI, 1989, pp. 20-24.

  17. Tudupova A.N., Strizhius V.E., Bobrovich A.V. Computational and experimental evaluation of fatigue life characteristics of the transport category aircraft composite wing panels. Aerospace MAI Journal, 2020, vol. 27, no. 4, pp. 21-29. DOI: 10.34759/vst-2020-4-21-29 −29

  18. Bokhoeva L.A., Kurokhtin V.Y., Perevalov A.V., Rogov V.E., Pokrovskii A.M., Chermoshentseva A.S. Helicopter structural elements and components fatigue resistance tests. Aerospace MAI Journal, 2017, vol. 24, no. 1, pp. 7-16.

  19. Aleshin N.P., Grigor’ev M.V., Shchipakov N.A. Inzhenernyi vestnik, 2015, no. 1, pp. 533-538.

  20. Murashov V.V., Rumyantsev A.F. Kontrol’. Diagnostika, 2007, no. 5, pp. 31-42.

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