Treatment of residual stress in failure assessment procedure

Abstract

The effect of residual stress on component failure has been investigated using the distributions from current failure assessment procedures, and a residual stress profile simple to apply with less conservatism has been proposed for the weld geometries of T-plate and tubular T-joint. The Stress intensity factors (SIFs) in the two weld geometries under various types of loads have been calculated using the Green's function method. The Green's functions were determined not only for the T-plate but also for the tubular T-joint with the built-in ends. The use of a linear (bending) stress profile, derived from an analysis of measured residual stress distributions in T-plate and tubular T-joints, has been examined. The profile was validated with experimentally measured residual stress distributions in two materials, a high strength and medium strength ferritic steel and two geometries, a T-plate joint and a tubular T-joint for crack lengths up to half the plate or pipe thickness. Whereas the recommended residual stress distributions are geometry and material specific, it is shown that a simplified linear bending profile provides a possible guideline, applicable to a range of materials and geometries, where detailed information on weld procedures or residual stress profiles are unavailable.

Consideration of the residual stress distributions in fatigue crack growth calculations for assessing welded steel joints

“…In this work, the calculated residual SIFs are compared with those that are reported for a welded T‐plate of medium and high‐strength steels from Refs . It is to be emphasized that the fatigue life of the welded joint and the effect of residual stresses and weld geometry can be evaluated if the solutions of K res and K app are known.…”

“…Until now, there is no WF applied to a general structure . More recent researches have found the general WF expression that can be used to approximate WFs for a variety of geometrical crack configurations.…”

“…The residual stress distributions and linear elastic stress intensity factors (SIFs) ( K res ) for plate T‐butt welds and tubular geometries have determined from a detailed finite element analysis and measurements of residual stress using neutron or x‐ray diffraction along the thickness direction of crack length from the weld toe up to half of the thickness t , (i.e. a / t = 0.5) . The resultant linear elastic SIF for these measured residual stress distributions, K res has been obtained using finite element method (FEM) software.…”

Assessment of the high-temperature crack behavior for a 316L stainless steel structure with defects

“…2. Weld residual stresses were induced on the specimen during the fabrication process [19,20]. However, it was shown that the residual stresses relaxed rapidly in high-temperature structures.…”

Discussion of “Hysteretic behavior of tubular joints under cyclic loading” by Wei Wang and Yi-Yi Chen in [Journal of Construction Steel Research 2007; 63(10):1384–1395, doi: 10.1061/j.jcsr.2006.12.002]

“…Residual stress patterns in tubular T-joint were investigated by Lee et al [2]. Residual stress patterns in tubular T-joint were investigated by Lee et al [2].…”