Weld toe versus root fatigue failure mode and governing parameters: A study of aluminum alloy load-carrying fillet joints

A post‐processing procedure for predicting high‐ and low‐cycle fatigue life of welded structures based on the master E–N curve

“…The co-authors of the paper performed a series of HCF tests on load/non-load carrying cruciform made from high-strength steel, 59 aluminum alloy, 62 and titanium alloy 58 Besides the fatigue experiments conducted by ourselves, we also collected several HCF and LCF fatigue data of different joint types made of various base metals. These fatigue data include the HCF data of T-and butt joints made of AZ31 magnesium alloy under load-controlled conditions (Figure 11C), 24,67 the low-cycle test of AA5083 deck panel joint (Figure 11D), 60 the LCF test of pipe joint made of SA-106B steel under displacement-control cantilever bending condition (Figure 11E), 61 the HCF test of AL5083/7005 cruciform joints (Figure 11F), 64 the LCF test of longitudinal gusset weld made of various highstrength steel under both load-and displacement-control condition (Figure 11G), 63 LCF test of fillet welds of ship structure under displacement-control condition (Figure 11I), 65 and LCF test of pipe joint made from A53-F carbon steel, under displacement-control fourpoint bending condition (Figure 11K).…”

“…The co‐authors of the paper performed a series of HCF tests on load/non‐load carrying cruciform made from high‐strength steel, 59 aluminum alloy, 62 and titanium alloy 58 (Figure 11A,F,H,I). The base metal of the steel joints is DH‐36 or HSLA‐80 steel, and all the aluminum joints are made from Al6082 alloy.…”

“…) corresponding to Δε s,i based on the master E-N curve; and D is fatigue damage fraction and the component is usually considered failure if D ≥ 1.F I G U R E 1 1 Fatigue data of different types of joint analyzed in this study: (A) HCF test of titanium cruciform joints,58 (B) HCF test of steel cruciform joints,59 (C) HCF test of T-and butt joints made from magnesium alloy,23 (D) LCF test of AA5083 deck panel joint,60 (E) LCF test of pipe joint under cantilever bending condition,61 (F) HCF test of AL6082 cruciform joints,62 (G) low-cycle fatigue test of longitudinal gusset weld,63 (H) high-cycle fatigue test of AL5083/7005 cruciform joints,64 (I) low-cycle fatigue test of fillet welds of ship structure,65 (J) LCF test of Q450 steel and T4003 stainless steel,49 and (K) low-cycle fatigue test of pipe joint under four-point bending condition 66. [Colour figure can be viewed at wileyonlinelibrary.com]…”

High-Cycle Fatigue Behaviour of the Aluminium Alloy 5083-H111

“…The results showed that the ULP increases the dislocation density significantly and refines the grains, leading to increased compressive residual stress and microhardness and inhibited crack initiation and propagation, resulting in a significant increase in vibration fatigue life. Xing et al [ 27 ] studied the transition fatigue failure of weld toe cracking and weld root cracking in aluminium fillet welds. Their experimental results showed that the weld root cracking has a lower fatigue life and wider scatter band than the weld toe cracking.…”

Fatigue life prediction of aluminum alloy T‐welded joints root failure based on equivalent crack method

“…10,11 Kang et al and Dong et al 12,13 proposed the structural stress method with the principal S-N curve, which effectively solved the problems of mesh sensitivity and difficult S-N curve selection in finite element analysis of welds. Recently, related scholars [14][15][16] proposed an analytical solution to determine the weld toe and root cracking of weld root traction stresses in load-bearing welded cruciform joints and proposed fatigue design recommendations for the joints. Each method has its merits and aims to determine the relevant parameters by avoiding uncertainties caused by stress or strain singularities at the toe or root of the weld.…”