About calculations of net-tension failure of a bolted joint on the weakened by hole cross-section of composite plate

Authors

DOI:

https://doi.org/10.20535/2521-1943.2018.82.121050

Keywords:

numerical 3D-modelling, composite, a bolt joint, strength, FEM

Abstract

Purpose. In order to carry out calculations of net-tension failure of the weakened cross-section of bolted joints with CFRP, it is necessary to estimate the value of the generalized stress concentration factor at the hole.

Methodology. Used a method of finite-elements and the 3D contact model as much as possible approached to real geometry and conditions of load application. Earlier, the authors created 24 3D models of samples of single-shear two-row bolted joint with CFRP (contact task), in which the structures of CFRP (6 variants) varied, as well as the side gap of bolts with holes (4 values).

The magnitude of the contraction force of the packet and the force that stretched the sample were unchanged. Based on the results of calculations, stress distributions are determined and stress concentration coefficients in CFRP plates at the holes (tables, graphs) are calculated.

Findings. Based on these results and additional calculations, the following conclusions were reached:

-in static strength analysis of net-tension failure of the weakened cross-section of bolted joints with CFRP, as a lower base estimate, one can take the value of the theoretical stress concentration factor  for a bolt-free hole in an orthotropic material plate, according to the formulas proposed by S.G. Lechnitsky;

- to obtain a generalized stress concentration factor  that takes into account the contact of the hole in the CFRP with the bolt, the value of the lower base estimate of  must be increased by a factor> 2, presumably  . The adjusted value of the correction factor  needs to be obtained in additional studies (natural or numerical), which will allow creating a database for values of  for the topical in the industry options for power bolted joints with composites.

Originality. The possible algorithms for estimating the static tensile strength of a weakened cross-section of bolted joints with CFRP are substantiated.

Author Biographies

K. Rudakov, Igor Sikorsky Kyiv Polytechnic Institute, Kyiv

ДПМиСМ, професор

Y. Dyfuchyn, Igor Sikorsky Kyiv Polytechnic Institute, Kyiv

ДПМиСМ

References

  1. Strizhius, V.E. (2014), “Method for Fatigue Life Analysis of Shear Joint Fasteners in Metal–Composit Joints of Aircraft Structural Elements”, Nauchnyi vestnik MGTU GA, no. 199(1).
  2. Vasilevskij, E.T., Dvejrin, A.Z., Karpov, Ja.S. and Krivenda, S.P. (2010), “System of experimental support for strength calculation of composites mechanical joints”, Otkrytye informacionnye i komp'juternye integrirovannye tehnologii, no. 47.
  3. Kirkach, A.B. (2011), “Problemy prochnosti boltovyh soedinenij na osnove sloistyh kompozicionnyh plastikov [Strength problems of bolted joints on the basis of layered composites]”, Vestnik HPI. Serija "Dinamika i prochnost' mashin". no. 63.
  4. Dvejrin, A.Z. (2014), “Review and analysis of problem state of experiment-calculated support of design of aircraft units from polymer composites with mechanical junction of parts”, Otkrytye informacionnye i komp'juternye integrirovannye tehnologii, no. 66.
  5. Rudakov, K.N. and Shukaev, S.N. (2013), “Modelling of Bolted Joint from PCM in the Program FEMAP/NX NASTRAN”, Journal of Mechanical Engineering NTUU Kyiv Polytechnic Institute”, no. 67.
  6. Krivov G.A. Matvienko, V.A., Rud'ko, A.N., Vasilevskij, E.T., Romanovich, G.N., Rudakov, K.N., Shukaev, S.N. and Dobronravov, A.A. (2013), “Numerical Study of Stress-Strain State of High-Loaded Joints of Airframe Structural Components”, Tehnologicheskie sistemy. Kyiv : UkrNIIAT, no. 4(65).
  7. Rudakov, K.N. and Shandura, A.S. (2015), “Numeral Ground of Application of mixed 3D-Modeley Composites at Computations of Bolted Joints”, Journal of Mechanical Engineering NTUU Kyiv Polytechnic Institute”, no. 2(74).
  8. Dyfuchyn, Y.N. and Rudakov, K.N. (2016), "Numerical Modelling of Bolted Joints from Composite. The Message 1. Creation of the Mixed 3D-Models", Journal of Mechanical Engineering NTUU Kyiv Polytechnic Institute”, no. 2(77). DOI: http://dx.doi.org/10.20535/2305‐9001.2016.77.76975.
  9. Rudakov, K., Shukaev, S., Krivov, G. and Matvienko, V. (2015), “Finite element analysis of the effect of technological factors on the strength of composite bolted joins”, Mechanotronic Systems and Materials 2014. Selected Papers. Opole University of Technology 2015.
  10. Kucher, N.K., Zarazovskij, M.N. and Danil'chuk, E.L. (2012), “Deformirovanie i prochnost' sloistyh ugleplastikov pri staticheskom termomehanicheskom nagruzhenii [Deformation and strength of laminated carbon-fiber-reinforced plastics under a static thermomechanical loading], Mehanika kompozitnyh materialov, vol. 48, no. 6.
  11. Fomichev, P.A. and Bojko, T.S. (2009), “Uchet koncentracii naprjazhenij v raschete dolgovechnosti jelementov konstrukcij po nominal'nym naprjazhenijam [The account of concentration of stresses in calculation of durability of elements of designs on rated stresses]”, Voprosy proektirovanija i proizvodstva konstrukcij letatel'nyh apparatov: sb. nauch. tr. Nac. ajerokosm. un-ta im. N.E. Zhukovskogo "HAI". vyp. 4 (60).
  12. GOST 25.602-80. Raschety i ispytanija na prochnost'. Metody mehanicheskih ispytanij kompozicionnyh materialov s polimernoj matricej (kompozitov). Metod ispytanija na szhatie pri normal'noj, povyshennoj i ponizhennoj temperaturah [Standard 25.602-80. Calculations and strength tests. Methods of mechanical trials of composite materials with a polymeric matrix (aggregates). The Test method on compression at the normal, raised and downgraded temperatures], Iz-vo standartov,Moscow,Russia.
  13. Dyfuchyn, Y.N. and Rudakov, K.N. (2016), "Numerical Modelling of Bolted Joints from Composite. The Message 2. Effect of the Backlash and PCM Structure on the Characteristics of the Stress-StrainStateof Bolts", Journal of Mechanical Engineering NTUU Kyiv Polytechnic Institute”, no. 3(78). DOI: http://dx.doi.org/10.20535/2305‐9001.2016.78.87475.
  14. Rudakov, K.M. and Dyfuchyn, Y.N. (2016), “Effect of the PCM Plate’s Structure on the Characteristics of the Stress-Strain State in the Areas of Holes of Bolted Joint with the PCM”, Tekhnolohycheskye systemy. no. 4(77).
  15. Dyfuchyn, Y. and Rudakov, K. (2017), "Numerical Modelling of Bolted Composite Joints. Bolts Rigidity Effect on NormalStresses in the Composite Layers", Mechanics and Advanced Technologies, no. 1(79). DOI: http://dx.doi.org/10.20535/2521-1943.2017.79.95756 .
  16. Dyfuchyn, Y. and Rudakov, K. (2017), “Analiz razryvnyh naprjazhenij i kojefficientov koncentracii naprjazhenij v zonah otverstij v plastinah s PKM obrazca boltovogo soedinenija [The analysis of explosive pressure and factors of concentration of stresses in zones of apertures in plates with polymeric composites the sample bolted joints]”, Voprosy proektirovanija i proizvodstva konstrukcij letatel'nyh apparatov: sb. nauch. tr. Nac. ajerokosm. un-ta im. N.E. Zhukovskogo "HAI". vyp. 3 (91).
  17. Bolotin, V.V. and Novichkov, Y.N. (1980), Mehanika mnogoslojnyh konstrukcij [Mechanic of multilayered structures], Mashinostroenie,Moscow,Russia.
  18. Reshetnikova R.Y. (2013), “Vlijanie osevogo natjaga na lokal'noe naprjazhennoe sostojanie v odnosreznyh boltovyh soedinenijah [Influence of an axial tightness on a local stresses condition in single-shear bolted joints]”, Voprosy proektirovanija i proizvodstva konstrukcij letatel'nyh apparatov: sb. nauch. tr. Nac. ajerokosm. un-ta im. N.E. Zhukovskogo "HAI". vyp. 1 (73).
  19. Prochnost'. Ustojchivost'. Kolebanija. Spravochnik v treh tomah. Tom 2 (1982), [Strength. Stability. Fluctuations. The handbook in three volumes. vol. 2], in I.A. Birgera, Ja.G. Panovko (ed.), Mashinostroenie,Moscow,Russia.
  20. Lehnicki, S.G. (1977), Teorija uprugosti anizotropnogo tela. Izd. 2-e. [Theory of elasticity of an anisotropic body. 2nd ed.], Nauka,Moscow,Russia.
  21. Timoshenko S. and Woinowsky-Krieger S. (1959), Theory of Plates and Shells. Second Edition.New YorkTorontoLondon: McGRAWHILL BGGK COMPANY, Inc.

Published

2018-05-01

How to Cite

[1]
K. Rudakov and Y. Dyfuchyn, “About calculations of net-tension failure of a bolted joint on the weakened by hole cross-section of composite plate”, Mech. Adv. Technol., no. 1(82), pp. 58–66, May 2018.

Issue

Section

Original study