Multiaxial fatigue of welded joints under in-phase and out-of-phase local strains and stresses

doi:10.1016/0142-1123(95)93051-3

International Journal of Fatigue

Volume 17, Issue 1, January 1995, Pages 55-70

https://doi.org/10.1016/0142-1123(95)93051-3 Get rights and content

Abstract

Welded cruciform-type specimens from fine-grained steel StE 290 and flange-tube as well as tube-tube joints from fine-grained steel StE 460 with unmachined and machined welds were investigated under biaxial constant-amplitude loading in the range 10³ to 5 × 10⁶ cycles to crack initiation and breakthrough respectively. In order not to interfere with residual stresses they were relieved by heat treatment. In-phase loading can be treated fairly well using the conventional hypotheses (von Mises or Tresca) on the basis of nominal, structural or local strains or stresses. But the influence of out-ofphase loading on fatigue life is severely overestimated if conventional hypotheses are used. However, the introduced hypotheses of the effective equivalent stress leads to fairly good predictions. For this, knowledge of local strains or stresses is necessary. They are determined by boundary-element analyses dependent on weld geometry. This hypothesis considers the influence of out-of-phase loading by taking into account the interaction of local shear stresses acting in different surface planes of the material. Further, size effects resulting from weld geometry and loading mode are included.

References (22)

ASME Boiler and Pressure Vessel Code, Section III, Division 1, Subsection NA, Article XIV-1212, Subsection NB-3352.4
(1984)
AD-Merkblatt S 2, Berechnung gegen Schwingbeanspruchung
(1982)
J.-Y. Yung et al.
A. Siljander et al.
C.M. Sonsino
DVS-Berichte
(1991)
C.M. Sonsino
Schwingfestigkeit von geschweissten Komponenten unter komplexen elasto-plastischen, mehrachsigen Verformungen
H. Neuber
Kerbspannungslehre-Theorie der Spannungskonzentration, Genaue Berechnung der Festigkeit
(1985)
J.-H. Yung et al.
Fatigue Fract. Eng. Mater. Struct.
(1985)

D. Radaj

Design and Analysis of Fatigue Resistant Welded Structures

(1990)

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Multiaxial fatigue of welded joints under in-phase and out-of-phase local strains and stresses

Abstract

ASME Boiler and Pressure Vessel Code, Section III, Division 1, Subsection NA, Article XIV-1212, Subsection NB-3352.4

AD-Merkblatt S 2, Berechnung gegen Schwingbeanspruchung

DVS-Berichte

Schwingfestigkeit von geschweissten Komponenten unter komplexen elasto-plastischen, mehrachsigen Verformungen

Kerbspannungslehre-Theorie der Spannungskonzentration, Genaue Berechnung der Festigkeit

Fatigue Fract. Eng. Mater. Struct.

Design and Analysis of Fatigue Resistant Welded Structures