Document Type: English

**Authors**

Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran

**Abstract**

In this paper, the effect of interference fit on fatigue life of holed plate of mechanical joints was investigated experimentally. Fatigue tests were carried out on the holed specimens of Al-alloy 7075-T6 alloy. The interference fit process consists of force fitting a fastener into the hole with a negative clearance (diameter of the fastener is larger than of the hole) that produces beneficial tangential pre-stress at the edge of the hole. Stress and strain analysis was implemented in order to estimate the fatigue life due to interference fit process. 3D finite element simulations have been performed to obtain stress and strain histories and distributions around the hole due to interference fit and subsequent cyclic longitudinal loading using ANSYS package. The results obtained from the finite element analysis of the interference fit were employed to predict the fatigue life. The fatigue life was divided into two phases of crack initiation life and fatigue crack growth life. Fatigue initiation life was estimated using Fatemi–Socie multiaxial fatigue criterion, and the fatigue crack growth life was predicted using AFGROW computer code. The results show that there is a good agreement between the numerically predicted total fatigue life and experimental fatigue test results

**Keywords**

[1] T.N. Chakherlou, J. Vogwell, “The effect of cold expansion on improving the fatigue life of fastener holes,” Eng. Fail. Anal, vol. 10, 2003, pp.13–24.

[2] Y.L. Wen, Y.L. Zhu, Sh. Hou, H. Sun, “Zhou Investigation on fatigue performance of cold expansion holes of 6061-T6 aluminum alloy,” Int. J. Fatigue, vol. 95, 2017, pp. 216–228.

[3] T.N. Chakherlou, R.H. Oskouei, J. Vogwell, “Experimental and numerical investigationof the effect of clamping force on the fatigue behaviour of bolted plates,” Eng. Fail. Anal, vol. 15. 2008, pp.563–574.

[4] T.N. Chakherlou, H. Taghizadeh, A.B. Aghdam, “Experimental and numerical comparison of cold expansion and interference fit methods in improving fatigue life of holed plate in double shear lap joints,” Aero. Sci. Tech, vol. 29, 2013, pp. 351–362.

[5] S. Kleditzsch, B. Awiszusa, M. Lätzer, E. Leidichb, “Numerical and analytical investigation of steel–aluminum knurled interference fits: Joining process and load characteristics,” J. Mater. Process. Tech, vol. 219. 2015, pp. 286–294.

[6] A. Mohammadpour, T.N. Chakherlou. “Numerical and experimental study of an interference fitted joint using a large deformation Chaboche type combined isotropic–kinematic hardening law and mortar contact method,” Int. J. Mech. Sci, vol. 106, 2016, pp.297–318.

[7] R. I. Stephens, A. Fatemi, R. Stephens, and H. O. Fuchs, “Metal Fatigue in Engineering,” John Wiley & Sons, New York, NY, USA, 2000.

[8] M.W. Brown, K.J. Miller, “A theory for fatigue failure under multiaxial stress–strain conditions,” Proc. Instit. Mech. Eng, vol. 187. 1973, pp.745–55.

[9] C. Ruiz, P.H.B. Boddington, K.C. Chen, “An investigation of fatigue and fretting in a dovetail joint,” Exp Mech, vol. 24. 1984, pp. 208–17.

[10] C.D. Lykins, S. Mall, V. Jain, “A shear stress-based parameter for fretting fatigue crack initiation,” Fatigue. Fract. Eng. Mater. Struct, vol. 24. 2001, pp. 461–73.

[11] D.L. McDiarmid, “A general criterion for high cycle multiaxial fatigue failure,” Fatigue. Fract. Eng. Mater. Struct,vol.14, 1991, pp. 429–53

[12] B. Crossland, “Effect of large hydrostatic pressures on the torsional fatigue strength of an alloy steel,” In: Proc. Int. Conf. on fatigue of metals, institution of mechanical engineers. London; 1956, p. 138–49.

[13] K. Smith, T. Topper, P. Watson, “A stress–strain function for the fatigue of metals (stress–strain function for metal fatigue including mean stress effect),” J Mater 1970;5:767–78.

[14] A. Fatemi, D.F. Socie, “A critical plane approach to multiaxial fatigue damage including out-of-phase loading,” Fatigue. Fract. Eng. Mater. Struct, vol. 11. 1988, pp. 149–65.

[15] J.C. Newman, E.P. Phillips, M.H. Swain, “Fatigue-life prediction methodology using small-crack theory,” Int. J. Fatigue, vol. 21. 1999, pp.109–19.

[16] D.V. Ramsamooj, “ Analytical prediction of short to long fatigue crack growth rate using small- and large-scale yielding fracture mechanics,” Int. J. Fatigue, vol. 25, 2003, pp. 923–33.

[17] M. Toyosada, K. Gotoh, T. Niwa, “Fatigue crack propagation for a through thickness crack: a crack propagation law considering cyclic plasticity near crack tip,” Int. J. Fatigue, vol. 26, 2004, pp. 983–992.

[18] AFGROW , “Fracture mechanics and fatigue crack growth analysis software tool,” 2008;Ver 4.12.15.0.

[19] M.R. Ayatollahi, S.M.J. Razavi, H.R. Chamani, “A numerical study on the effect of symmetric crack flank holes on fatigue life extension of a SENT specimen,” Fatigue. Fract. Eng. Mate.r Struct, vol. 37, 2014, pp.1153–1164.

[20] M.R. Ayatollahi, S.M.J. Razavi, M.Y. Yahya, “Mixed mode fatigue crack initiation and growth in a CT specimen repaired by stop hole technique,” Fract. Eng. Mate.r Struct, vol. 145, 2015, pp.115–127.

[21] Z. Li, J. Duan, “The effect of a plastically deformed zone near crack tip on the stress intensity factors,” Int. J. Fract , vol. 117, 2002, pp. 29–34.

[22] R. Zhou, P. Zhu, Z. Li, “The shielding effect of the plastic zone at mode-II crack tip,” Int. J. Fract, vol. 171, 2011, pp. 95–200.

[23] J. J. Warner, P. N. Clark , D. W. Hoeppner, “Cold expansion effects on cracked fastener holes under constant amplitude and spectrum loading in the 2024-T351 aluminum alloy,” Int. J. Fatigue, vol. 36, 2014, pp. 983–992.

[24] D. L. Andrew, P. N. Clark, D. W. Hoeppner, “Investigation of cold expansion of short edge margin holes withpre-existing cracks in 2024-T351 aluminium alloy,” Fatigue. Fract. Eng. Mate.r Struct, vol. 37, 2014, pp.406–416.

[25] E. Giner, C. Navvaro, M. Sabsabi, M. Tur, J. Dominguez, F.J. Fuenmayor, “Fretting fatigue life prediction using the extended finite element method,” Int. J. Mech, Sci, vol. 53, 2011, pp.217–25.

[26] H. Taghizadeh, T.N. Chakherlou, H. Ghorbani, A. Mohammadpour. “Prediction of fatigue life in cold expanded fastener holes subjected to bolt tightening in Al alloy 7075-T6 plate,” Int. J. Mech, Sci, vol. 90, 2015, pp.6–15.

[27] Swanson Analysis Systems Inc. ANSYS, Structural nonlinearities, User’s Guide for Revision 13.

[28] N. E. Dowling, Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture, and Fatigue: Prentice Hall, 1993.

[29] G. Glinka and R. I. Stephens, “Total fatigue life calculations in notch SAE cast steel under variable loading spectra,« ASTM STP 791, 1983, pp. 427-445.

[30] R. Dhamari, “The effect of water-displacing corrosion preventives on the fatigue behaviour of mechanically fastened aluminium joints,« Ph.D. Thesis, University of New South Wales, 2004.

[31] Y. Xiang, Z, Lu, Y. Liu, “Crack growth-based fatigue life prediction using an equivalent initial flaw

model. Part I: Uniaxial loading.” Int. J. Fatigue, vol. 32, 2010, pp. 341–349.

[32] H. Liu , D.-G. Shang, J.-Z. Liu, Z.K. Guo, “Fatigue life prediction based on crack closure for 6156 Al-alloy laser welded joints under variable amplitude loading,” Int. J. Fatigue, vol. 72, 2015, pp. 11–18.

[33] A.S.F. Alves, L.M.C.M.V. Sampayo, J.A.F.O. Correia , A.M.P. De Jesus, P.M.G.P. Moreira , P.J.S. Tavares, “Fatigue life prediction based on crack growth analysis using an equivalent initial flaw size model: Application to a notched geometry,” Proc. Eng,vol. 114, 2015, pp.730 – 737.

Volume 10, Issue 4

Autumn 2017

Pages 15-32