TY - JOUR A1 - Schork, B. A1 - Zerbst, Uwe A1 - Kiyak, Yusuf A1 - Kaffenberger, M. A1 - Madia, Mauro A1 - Oechsner, M. T1 - Effect of the parameters of weld toe geometry on the FAT class as obtained by means of fracture mechanics-based simulations JF - Welding in the World N2 - The fracture mechanics-based IBESS approach is applied to the determination of FAT classes of butt welds with crack Initiation along the weld toe. The aim is an investigation of the effect of the geometrical parameters toe radius, flank angle, reinforcement and secondary notches such as roughness or undercuts. The influence of these parameters is discussed both individually and in combination; however, excluding statistical distributions of them and the material data. The results, when compared with conventional FAT classes for butt welds, are encouraging with respect to a potential contribution of IBESS to the discussion of more advanced quality criteria for welds. To that purpose, demands for further research are proposed. KW - Fracture mechanics KW - Weld toe geometry KW - Fatigue crack initiation KW - FAT class approach PY - 2020 DO - https://doi.org/10.1007/s40194-020-00874-7 IS - 64 SP - 925 EP - 936 PB - Springer AN - OPUS4-53079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Kiyak, Yusuf A1 - Breidung, Marc A1 - Baer, Wolfram A1 - Küppers, M. ED - Madia, Mauro T1 - Stiffness/constraint effects in analytical flaw assessment - A technical note JF - Engineering Fracture Mechanics N2 - Using the case study of a fail-safe design criterion for a steering knuckle of a commercial vehicle, the effect of stiffness/constraint on the crack driving force in the component is discussed. The problem arises when assessment procedures such as R6, BS 7910 or SINTAP/FITNET are applied in conjunction with substitute geometries for determining the model parameters K-factor and limit load (or a substitute for the latter), as it is common practice. In the example, the conservatism was so pronounced that this procedure was in fact unusable. A way out could be the finite element-based determination of the model parameters and their use in the analytical framework. This procedure is useful and effective if the finite element-based calculations are used in parameter sensitivity analyses. KW - Fail-safe design KW - Fracture resistance KW - Fracture assessment KW - Stiffness KW - Constraint PY - 2022 DO - https://doi.org/10.1016/j.engfracmech.2022.108728 SN - 0013-7944 IS - 273 SP - 1 EP - 15 PB - Elsevier Science CY - Kidlington AN - OPUS4-55544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Madia, Mauro A1 - Kiyak, Yusuf A1 - Zerbst, Uwe T1 - Extended parametric equations for weld toe stress concentration factors and through-thickness stress distributions in butt-welded plates subject to tensile and bending loading JF - Weld World N2 - Based on a large set of 2D finite element analyses, parametric equations for weld toe stress concentration factors and through-thickness stress profiles are provided for butt-welded plates. These cover Single-Vand Double-V joints subject to tensile and bending loading. Compared to the most widespread solutions in the literature, which have also been tested against the finite element data in this work, the application range is extended particularly with respect to the weld toe radius(0.1≤ρ≤4 mm)andangle(10 °≤α≤60 °). Furthermore, two values of excess weld metal are considered (h=0.75;2.5mm). The analyses are performed for a plate thickness of 10 mm. Besides the extended validity range, the proposed equations show also an improved accuracy compared to the existing solutions. KW - Butt welds KW - Weld toes KW - Stress analysis KW - Structures PY - 2016 DO - https://doi.org/10.1007/s40194-016-0377-x VL - 60 IS - 6 SP - 1247 EP - 1259 AN - OPUS4-37959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Kiyak, Yusuf A1 - Madia, Mauro A1 - Burgold, Andreas A1 - Riedel, Gernot T1 - Reference loads for plates with semi-elliptical surface cracks subjected to tension and bending for application within R6 type flaw assessment JF - Engineering fracture mechanics N2 - Two of the authors of the present paper proposed a definition of a reference load F0 which can be used as an alternative option to the common limit load for cases where the definition of the latter might be problematic in the frame of flaw assessment procedures such as R6, BS 7910, SINTAP or FITNET. The reference load is defined as that load at which the ligament yielding parameter Lr approaches one. F0, in general, varies along the crack front. It has to be obtained by finite element analyses but the results can be approximated by analytical expressions. In a previous study of the authors such a solution was presented for tension loaded plates with semi-elliptical surface cracks. In the present paper it is extended to pure bending and to combined bending and tension. KW - Flaw assessment KW - R6 procedure KW - BS 7910 KW - SINTAP KW - FITNET KW - Limit load KW - Reference load PY - 2013 DO - https://doi.org/10.1016/j.engfracmech.2012.11.017 SN - 0013-7944 SN - 1873-7315 VL - 99 SP - 132 EP - 140 PB - Elsevier Science CY - Kidlington AN - OPUS4-30416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -