Parametric equations for notch stress concentration factors of rib—deck welds under bending loading

2021 ◽  
Author(s):  
Qiudong Wang ◽  
Bohai Ji ◽  
Zhongqiu Fu ◽  
Yue Yao
Keyword(s):  
Stress Concentration ◽  
Notch Stress ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Bending Loading

scholarly journals Stress analysis of V-notches with and without cracks, with application to foreign object damage

2003 ◽  
Vol 38 (5) ◽  
pp. 429-441 ◽  
Author(s):  
D Nowell ◽  
D Dini ◽  
P Duó
Keyword(s):  
Stress Intensity ◽  
Stress Concentration ◽  
Fatigue Cracks ◽  
Leading Edge ◽  
Foreign Object ◽  
Foreign Object Damage ◽  
Hard Particles ◽  
Notch Stress ◽  
Concentration Factors ◽  
Stress Concentration Factors

Gas turbine engines can be subject to ingestion of small hard particles, leading to foreign object damage. This can take the form of sharp V-notches in the leading edge of blades and there is a need to predict the initiation and propagation behaviour of fatigue cracks growing from the base of the notch. The notch geometry is quite extreme and is not normally covered in standard references for notch stress concentration factors. Similarly, stress intensity factor solutions for this geometry are not widely available. This paper uses the dislocation density approach to solve the two-dimensional elastic problem of a V-notch with a radiused root. Stress concentration factors are found for the notch itself, and stress intensity factors are determined for cracks growing away from the notch for cases of applied and residual stress distributions. Comparisons are made with existing notch solutions from the literature.

Closed-form functions for elastic stress concentration factors in notched bars

1995 ◽  
Vol 30 (2) ◽  
pp. 143-154 ◽  
Author(s):  
T G F Gray ◽  
F Tournery ◽  
J Spence ◽  
D Brennan
Keyword(s):  
Stress Concentration ◽  
Closed Form ◽  
Elastic Stress ◽  
Elliptical Hole ◽  
Notch Stress ◽  
Double Edge ◽  
Field Intensity Factors ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Practical Accuracy

The closed-form equations given are based on the results of finite element analyses of double-edge-notched plates subject to tension or in-plane bending. The notch dimensions were varied in a parametric survey from shallow, part-circular forms to deep, sharp, slits with semi-circular ends, giving stress concentration factors varying from 1.2 to 13 (net stress basis). The concept of a configuration factor for notches, similar to that used to calculate crack-tip stress field intensity factors, is introduced. It is shown in the first instance that the analogous crack configuration factor can be used directly to modify the elastic stress concentration factor for an elliptical hole, giving closed-form functions that do not involve empirical fitting constants and have acceptable practical accuracy. Reasons for the effectiveness of this form are given, together with an analysis of the points where the notch stress concentration factors diverge from the simple closed form. Further refinements that improve accuracy are given and comparisons are also made with stress concentration factors for hyperbolic edge notches.

Spot-welded joints subjected to shear-tension loading. Part 1: Notch stress and strain range predictions and estimates for repeated loading

2005 ◽  
Vol 40 (8) ◽  
pp. 739-754 ◽  
Author(s):  
A. R Gowhari-Anaraki ◽  
S J Hardy ◽  
B Fardad
Keyword(s):  
Steady State ◽  
Stress Concentration ◽  
Elastic Stress ◽  
Strain Range ◽  
Stress And Strain ◽  
Notch Stress ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Tension Loading ◽  
Spot Welded

A three-dimensional finite element model has been used to study the cyclic elastic-plastic stress and strain characteristics of a spot-welded joint subjected to repeated shear-tension loading. Four geometries, having low, medium, and high notch elastic stress concentration factors, are considered in this investigation. Two simple material behaviour models, e.g. elastic-perfectly plastic and kinematic hardening, are assumed. All results have been normalized with respect to material properties so that they can be applied to all geometrically similar spot-welded joints from other materials, which may be represented by the same material models. Normalized maximum steady state strain ranges are plotted as a function of the nominal load for the range of material hardening assumptions and notch elastic stress concentration factors. These plots can be used in the low cycle fatigue life design of such geometrically similar spot-welded specimens. The paper also compares finite element steady state strain range predictions with values estimated using simple notch stress-strain conversion rules for the four geometries and a range of nominal stresses. From this study, a ‘notch plastic flow sensitivity factor’, qp, to be used in conjunction with an intermediate rule, is suggested for estimating the strain range. Finally, a strain range estimate methodology, based on the notch elastic stress concentration factor, coupled with a multiaxial fatigue criterion and an intermediate rule, is then developed for this type of specimen and loading.

Stress and Notch-Stress Concentration Induced by Slight Depressions and Protrusions

1993 ◽  
Vol 60 (4) ◽  
pp. 992-997 ◽  
Author(s):  
C. H. Wu
Keyword(s):  
Stress Concentration ◽  
Aspect Ratio ◽  
Asymptotic Expansions ◽  
Surface Stress ◽  
Analytic Solution ◽  
Small Aspect Ratio ◽  
Regular Perturbation ◽  
Notch Stress ◽  
Concentration Factors ◽  
Stress Concentration Factors

The presence of a smooth depression on the surface of a stretched half-plane magnifies the surface stress at the trough of the depression. Similarly, the stress at the foot of a smooth protrusion is also magnified. The associated stress concentration factors are determined, via a regular perturbation procedure, in terms of a small aspect ratio that measures the slight unevenness of the surf ace. When the depression/protrusion profile has corners, the method of matched asymptotic expansions is used to obtain the desired analytic solution. The case of a shallow notch, as well as that of a triangular protrusion, is solved explicitly.

scholarly journals Stress Concentration Factors for Welded Plate T-Joints Subjected to Tensile, Bending and Shearing Loads

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 546
Author(s):  
Krzysztof L. Molski ◽  
Piotr Tarasiuk
Keyword(s):  
Stress Concentration ◽  
Plate Thickness ◽  
Percentage Error ◽  
Geometrical Parameters ◽  
T Joints ◽  
Loading Mode ◽  
Weld Toe ◽  
Concentration Factors ◽  
Parametric Expression ◽  
Stress Concentration Factors

The paper deals with the problem of stress concentration at the weld toe of a plate T-joint subjected to axial, bending, and shearing loading modes. Theoretical stress concentration factors were obtained from numerical simulations using the finite element method for several thousand geometrical cases, where five of the most important geometrical parameters of the joint were considered to be independent variables. For each loading mode—axial, bending, and shearing—highly accurate closed form parametric expression has been derived with a maximum percentage error lower than 2% with respect to the numerical values. Validity of each approximating formula covers the range of dimensional proportions of welded plate T-joints used in engineering applications. Two limiting cases are also included in the solutions—when the weld toe radius tends to zero and the main plate thickness becomes infinite.

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