Stress and strain range predictions for axisymmetric and two-dimensional components with stress concentrations and comparisons with notch stress-strain conversion rule estimates

Abstract

A comparison is made between finite element predictions of strain and strain range for hollow tubes with axially loaded axisymmetric internal projections and values obtained from the simple notch stress-strain conversion (NSSC) rules. Data from other published analyses, where notch strains were predicted, support this investigation. The comparison is made for a variety of monotonic and cyclic loads, material hardening assumptions, and geometries. An intermediate rule (m = 0.5) which appears to correlate with the finite element predictions to a reasonable degree of accuracy, is identified. In addition, an analytical relationship is suggested for calculating strain and strain range, in terms of load level, strain hardening assumption, and elastic stress concentration factor (SCF) for this type of axisymmetric component. Also, a comparison is made between some previously published experimental and numerical data, obtained for other two-dimensional and axisymmetric problems, and NSSC rule estimates in order to confirm the suitability of the intermediate rule. Finally, on the basis of these comparisons, an approximate procedure for predicting stress and strain ranges under conditions of gross yielding is presented for plane stress, plane strain, and axisymmetric problems.

Optimal design of machine components using notch correction and plasticity models

“…Fatigue crack initiation life predictions for notched specimens or components are usually based on the LSA and fatigue data obtained from simple uniaxial unnotched specimen tests, where it is assumed that smooth and notched specimens with the same local strain range experience the same number of cycles to fatigue failure [1,25].…”

“…3. Using approximate elasto-plastic stress-strains relations like notch correction (NC) rules, known also as notch stress-strain conversion (NSSC) rules [25].…”

“…Hardy and Gowhari-Anaraki [25] r eq e t eq ¼ K 2 teq r a e a ðmonotonic loadingÞ; Dr eq De t eq ¼ K 2 teq Dr a De a ðcyclic loadingÞ;…”

Mixed-mode fatigue crack propagation in thin T-sections under plane stress

“…It is worth noting that the maximum J value can be calculated by substituting aˆ45¯in equations (15) to (20), i.e. J maxˆJ45 .…”

“…The J value provides an important controlling parameter in the fatigue crack propagation process under small-scale yielding conditions. Estimated values of F c,e , calculated using equations (15) to (20), are plotted in Fig. 15 for a typical geometry …h=d0 :5, w=dˆ3, r=dˆ0:05 † and crack initiation lengths of 0.5 and 2.5 mm.…”