Overload failure curve and fatigue behavior of spot-welded specimens

Strength assessment of spot-welded sheets of interstitial free steels

“…Similar report by Kavamura and Batalha (2008) indicates the ratio of failure loads under pure-shear (P PS f ) and pure-tension (P CT f ) configurations as 0.811 (0.8 mm thickness) and 0.818 (1.2 mm thickness) for sheets of a mild steel of 170 MPa yield strength. The present results (Table 6) Lee et al (2005a) indicate higher values of P CT f /P TS f as 0.908 and 0.870 for weld nugget diameters of 4.95 and 5.9 mm, respectively. The above analyses show that the experimental results are closer to the theoretical predictions of P CT f /P TS f (=0.735) based on Von Mises' criterion.…”

“…11. The observed nature of the hardness profiles are similar to the ones reported by Lee et al (2005a), Lamouroux et al (2007), Choi et al (2007) and Chang et al (2001). The base metal, HAZ and the fusion zone of the spotwelds are considered to exhibit some characteristic average hardness value; these are estimated and are compiled in Table 4.…”

“…The hardness of the fusion zone and the HAZ is found to be 60% and 24% higher than the hardness of the base metal in EIF steel; the corresponding increase of hardness for these zones in HIF steel are 64% and 27%, respectively. Lee et al (2005a) have reported 76% and 38% higher hardness of the fusion zone and HAZ, respectively, than that of the base metal in The base metal, HAZ and the fusion zone exhibit predominantly ferrite. But there exists some difference in the morphology of ferrite in the different zones of spot-weld as discussed in the preceding section.…”

Predicting the failure of ultrasonic spot welds by pull-out from sheet metal

“…A limitation of these approaches is that fracture generally involves considerations of energy in addition to considerations of strength, and, therefore, purely strength-based approaches to fracture are not expected to give geometry-independent predictions. There have also been studies that have approached the problem of weld failure from an energy-based approach, using linear-elastic fracture-mechanics (Zhang, 1997(Zhang, , 1999(Zhang, , 2001Lee et al, 2005). However, these approaches are limited to systems dominated by elasticity or small-scale yielding (small compared to the thickness of the sheet metal and to the size of the weld).…”

Mode I Fracture at Spot Welds in Dual-Phase Steel: An Application of Reverse Digital Image Correlation

“…Validation of existing spot-weld failure criteria has been explored with analytical approaches wherein the stress distribution around a weld is related to the far field failure load [14,15,[18][19][20][21][22][23] and with finite element failure simulations [24,25]. There are numerous reports in the literature aimed at predicting failure of spot welds under various loading conditions such as tension [23], shear [23], combined tensile/shear [16,23,26], impact [27], and fatigue [28,29]. Test specimens with different geometries (e.g.…”