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Effect of laser heating on mechanical properties, residual stresses and retardation of fatigue crack growth in AA2024
Author(s) -
Kashaev Nikolai,
Groth Anne,
Ventzke Volker,
Horstmann Manfred,
Riekehr Stefan,
Staron Peter,
Huber Norbert
Publication year - 2021
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.13400
Subject(s) - materials science , residual stress , paris' law , ultimate tensile strength , crack closure , rivet , fatigue limit , composite material , laser , strength reduction , transverse plane , stress concentration , reduction (mathematics) , fracture mechanics , structural engineering , optics , finite element method , physics , geometry , mathematics , engineering
Local laser heating treatment using a defocussed laser beam was applied to the surface of 2‐mm‐thick AA2024‐T3 sheets. Two different treatment designs—namely, lines and circles—as well as the positioning and number of treatments were investigated regarding their potential to retard the propagation of through‐thickness fatigue cracks. The highest fatigue crack growth life extension of 285% was achieved by the application of four laser heating lines or two circles on each specimen side. The induced compressive residual stress field through the LH process is primarily responsible for an improvement in fatigue crack growth life. An emphasis was placed on investigating the effect of the treatment on the possible reduction of tensile and fatigue strength (S‐N life). If only one line was applied transverse to the loading direction or only one circle was used, the reduction of fatigue strength was comparable to the reduction of fatigue strength resulting from the stress concentration introduced due to the presence of a rivet hole.