Fatigue life prediction in AlMgSi1 lap joint weldments

The fatigue behaviour of an AlMgSi1 alloy lap welded joint and the improvement in fatigue strength due to post-weld heat treatment were investigated. Two series of fatigue tests were performed: one in as-welded specimens and another in heat-treated specimens. The prediction of crack initiation life under a plane strain condition was made based on the local strain approach using Morrow's modified equation. The local inelastic stresses and strains at the weld toe were calculated for the heat-treated specimens using three methods: Neuber, Glinka and finite element analysis. The accuracy of the different methods were evaluated and discussed.

[1]  M. N. James,et al.  Fatigue performance of 6261-T6 aluminium alloy – constant and variable amplitude loading of parent plate and welded specimens , 1997 .

[2]  J. R. Griffiths,et al.  CASTING DEFECTS AND THE FATIGUE BEHAVIOUR OF AN ALUMINIUM CASTING ALLOY , 1990 .

[3]  Tim Topper,et al.  NEUBER'S RULE APPLIED TO FATIGUE OF NOTCHED SPECIMENS , 1967 .

[4]  N. Dowling.  Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture, and Fatigue , 1993 .

[5]  Saburo Usami,et al.  Cyclic Strain and Fatigue Strength at the Toes of Heavy Welded Joint : Fracture Mechanics Analysis of Fatigue Strength of Welded Joints, 3rd Report , 1978 .

[6]  J. Morrow.  Cyclic Plastic Strain Energy and Fatigue of Metals , 1965 .

[7]  D. Radaj,et al.  Review of fatigue strength assessment of nonwelded and welded structures based on local parameters , 1996 .

[8]  José Costa,et al.  Fatigue crack initiation in notched specimens of 17Mn4 steel , 1993 .

[9]  Rl Meltzer,et al.  Generalized Application of Neuber's Rule , 1980 .

[10]  F. V. Lawrence,et al.  Constant amplitude and variable load history fatigue test results and predictions for cruciform and lap welds , 1984 .

[11]  S. J. Maddox.  Fatigue Design Optimisation in Welded Joints , 1989 .

[12]  K. Bathe.  Finite Element Procedures , 1995 .

[13]  D. Radaj,et al.  Prediction of service fatigue strength of a welded tubular joint on the basis of the notch strain approach , 1998 .

[14]  Małgorzata Skorupa.  FATIGUE CRACK INITIATION LIFE PREDICTION FOR WELDED JOINTS BY LOW CYCLE FATIGUE APPROACH , 1990 .

[15]  B. Lazan.  Internal Friction, Damping, and Cyclic Plasticity , 1965 .

[16]  Grzegorz Glinka,et al.  Fatigue analysis of manufacturing defects in weldments , 1986 .

[17]  H. Neuber.  Theory of Stress Concentration for Shear-Strained Prismatical Bodies With Arbitrary Nonlinear Stress-Strain Law , 1961 .

[18]  G. Glinka,et al.  A method of elastic-plastic stress and strain calculation at a notch root , 1981 .

[19]  Richard C. Rice,et al.  Fatigue design handbook , 1988 .

[20]  M. N. James.  Constant and variable amplitude loading of 6261 aluminium alloy I-beams with welded cover plates—Influence of weld quality and stress relief , 1997 .

[21]  Grzegorz Glinka,et al.  Energy density approach to calculation of inelastic strain-stress near notches and cracks , 1985 .

[22]  K. Chawla,et al.  Mechanical Behavior of Materials , 1998 .

[23]  Cetin Morris Sonsino,et al.  Fatigue assessment of welded joints by local approaches Second edition , 2007 .

[24]  Vigilio Fontanari,et al.  Influence of post weld treatments on the fatigue behaviour of Al-alloy welded joints , 1998 .

[25]  E. G. Ellison,et al.  ELASTIC-PLASTIC BEHAVIOUR AND UNIAXIAL LOW CYCLE FATIGUE LIFE OF NOTCHED SPECIMENS , 1995 .

[26]  Bahram Farahmand,et al.  Fatigue and fracture mechanics of high risk parts , 1997 .