Residual stress effect on fatigue striation spacing in a cold-worked rivet hole P.F.P. de Matos a, * , P.M.G.P. Moreira a , J.C.P. Pina b , A.M. Dias c , P.M.S.T. de Castro a a Department of Mechanical Engineering and Industrial Management, Faculty of Engineering, University of Porto, Rua Dr Roberto Frias, Porto 4200-465, Portugal b Department of Physics, University of Coimbra, 3004-516 Coimbra, Portugal c Department of Mechanical Engineering, University of Coimbra, 3004-516 Coimbra, Portugal Available online 22 September 2004 Abstract The residual stress effect due to cold-working is studied in relation to fatigue striation spacing. Cold-working introduces a compressive stress field around the hole reducing the tendency for fatigue cracks to initiate and grow under cyclic mechanical loading. It is known that fatigue lifetime assessment requires a detailed knowledge of the residual stress profile. X-ray diffraction and 3D finite element analysis (FEA) can be used to determine the resid- ual stress profile. Scanning electron microscopy (SEM) measurements were performed for measuring the striation spacing. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: X-ray diffraction; Residual stress; Finite element analysis; Scanning electron microscopy; Striation spacing 1. Introduction Problems related with ageing aircraft may be re- duced by enhancing the fatigue performance, espe- cially in critical zones, acting as stress raisers, such as access and riveted holes. Fastener hole fatigue strength may be enhanced by creating compressive residual circumferential stresses around the hole. This technique (cold-work) has been used in the aeronautical industry for the past thirty years to delay fatigue damage and retard crack propaga- tion. Research has been concentrated mainly on modelling the residual stress field using analytical or numerical two-dimensional (2D) or three- dimensional (3D) methods [1–5], on the experi- mental measurement of the residual stress field 0167-8442/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.tafmec.2004.08.003 * Corresponding author. E-mail address: pfpmatos@fe.up.pt (P.F.P. de Matos). Theoretical and Applied Fracture Mechanics 42 (2004) 139–148 www.elsevier.com/locate/tafmec