Asian Journal of Scientific Research1992-14542077-2076Asian Network for Scientific Information10.3923/ajsr.2013.518.527KaruppananS. HashimM.H. WahabA.A. 3201363In the aerospace industry, the fastener holes are widely present because various
mechanical parts need to be connected by rivets or bolts. These holes experience
external forces which cause a tensile stress on the surface resulting in fatigue
cracks and eventually fatigue failure of the structure. To alleviate this problem,
cold expansion method has been used to improve the fatigue behavior of structures
by inducing compressive residual stresses around the holes by forcing a tapered
mandrel through the fastener hole that is slightly smaller than the mandrel.
In this study, finite element simulations had been carried out for cold expansion
process in order to determine the residual stress fields around two cold-expanded
holes by varying the centre distance between two holes and also the thickness
of the material. Moreover, the effect of through thickness position has also
been investigated by considering the residual stresses distribution at different
positions such as at the entrance face, at the middle of the thickness and at
the exit face of the material. Aluminium alloy 7075-T6 was used as the material
for the model simulated in ANSYS. The results showed that as the distance between
the adjacent holes increased, the residual stresses decreased. Moreover, the
simulation also highlighted the effect of the plate thickness and the through
thickness position on the residual stresses distribution. The compressive residual
stresses increased as the plate thickness increased. Meanwhile, the results
at the mid-thickness were higher than the results at the entrance and exit faces.]]>Ball, D.L. and D.R. Lowry,1998211734Houghton, S.J. and S.K. Campbell,2012357483Ismonov, S., S.R. Daniewicz, J.C. Newman, Jr., M.R. Hill and M.R. Urban,20092009Wei, K.S. and S. Karuppanan,20111118391844Kim, C., W.H. Yang, G.D. Sung and M.H. Go,20019198204Kim, C., W.H. Yang, S.P. Heo and K.H. Chung,2002304652Kim, C., D.J. Kim, C.S. Seok and W.H. Yang,2004153-154986991Link, R.E. and R.J. Sanford,199027599604Mahendra Babu, N.C., T. Jagadish, K. Ramachandra and S.N. Sridhara,200815339348Nigrelli, V. and S. Pasta,2008205290296Ozdemir, A.T. and R. Hermann,19993412431252Papanikos, P. and S.A. Meguid,19984010191028Papanikos, P. and S.A. Meguid,199992-93424428Pavier, M.J., C.G.C. Poussard and D.J. Smith,199833275289