Thin circular hollow section-to-plate T-joints: Stress concentration factors and fatigue failure under in-plane bending

2006 ◽  
Vol 44 (2) ◽  
pp. 159-169 ◽  
Author(s):  
Fidelis Rutendo Mashiri ◽  
Xiao-Ling Zhao
Keyword(s):  
Stress Concentration ◽  
Fatigue Failure ◽  
T Joints ◽  
Hollow Section ◽  
Concentration Factors ◽  
Plane Bending ◽  
Stress Concentration Factors ◽  
Circular Hollow Section

scholarly journals Stress Concentration Factors (SCFs) in Circular Hollow Section CHS-to-H-shaped Section Welded T-Joints under Axial Compression

2019 ◽  
Vol 5 (1) ◽  
pp. 33 ◽  
Author(s):  
Abderlahman Ismaeel Hamdan
Keyword(s):  
Stress Concentration ◽  
Axial Compression ◽  
Welded Joints ◽  
Thickness Ratio ◽  
Geometrical Parameters ◽  
Hollow Section ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Circular Hollow Section ◽  
Shaped Section

The aim of this paper is to investigate the effects of non-dimensional geometric parameters on stress concentration factors (SCFs) of circular hollow section CHS brace-to-H-shaped section T-connections under axial compression. This type of welded joints is used increasingly in steel construction. However, its fatigue design is not covered by codes, and its fatigue strength has not been given the deserved attention by researchers.  This research, however, bridges the gab on SCFs in this type of welded connections when being loaded in axial compression. here, parametric study based on the numerical analysis was performed to evaluate the effect of CHS brace diameter to H-shaped chord flange width ratio (β), H-shaped chord flange width to thickness ratio (2γ) and CHS brace thickness to H-shaped chord flange thickness ratio (τ) on SCFs in the brace and the chord of the connection. Based on practical considerations, the validity range of these parameters was 0.3 ≤ β ≤ 0.7, 16 ≤ 2γ ≤ 30 and 0.2 ≤ τ ≤ 0.1. Three-dimensional finite element (FE) study using commercial software ABAQUS was performed to study the hot spot stress distribution and hence SCFs in this type of welded joints. To begin with, the results of FEM were verified against available experimental data and good agreement was achieved. Afterwards, 48 joints were modeled in Abaqus to study the effect of geometrical parameter on SCFs in brace and chord. Based on the results of this extensive study, the effect of geometrical parameters was revealed. The paper, thus, shows that whilst β increases, SCFs in the brace and chord increases. Moreover, increasing the parameter 2γ results in an increase in SCFs in the two members. However, the change in τ has no significant effect on the SCFs in the brace or the chord. Values of SCFs are found to be between 2 and 7.

STRESS CONCENTRATION FACTORS AND FATIGUE FAILURE OF WELDED T-CONNECTIONS IN CIRCULAR HOLLOW SECTIONS UNDER IN-PLANE BENDING

2004 ◽  
Vol 04 (03) ◽  
pp. 403-422 ◽  
Author(s):  
FIDELIS RUTENDO MASHIRI ◽  
XIAO-LING ZHAO ◽  
PAUL GRUNDY
Keyword(s):  
Stress Concentration ◽  
Failure Criterion ◽  
Fatigue Behavior ◽  
Design Guidelines ◽  
T Joints ◽  
Fatigue Design ◽  
Concentration Factors ◽  
Thin Walled ◽  
Plane Bending ◽  
Stress Concentration Factors

The fatigue behavior of welded thin-walled T-joints made up of both circular hollow section (CHS) braces and chords, subjected to cyclic in-plane bending, is described in this paper. CHS chords and braces are of thicknesses less than 4 mm. Current fatigue design guidelines show that the design of welded tubular nodal joints is restricted to thicknesses greater than or equal to 4 mm. The increased availability and use of thin-walled (t<4 mm) tubes of high-strength steels in recent years, in structures subjected to cyclic loading, means that it is important to study the fatigue behavior of welded thin-walled tubular nodal joints. In this paper, welded thin-walled CHS-CHS T-joints subjected to constant-stress-amplitude cyclic in-plane bending range are studied. The stress concentration factors (SCFs) determined experimentally at the brace and chord crown positions are shown to be about 30% and 40% respectively of the SCFs determined using parametric equations in existing fatigue design guidelines. The fatigue tests showed that in welded thin-walled CHS-CHS T-joints, a through-thickness crack occurs when the surface crack length along the weld toes in the chord has grown to a length equal to about 40% of the circumference of the brace member. An end of test failure criterion was proposed as an alternative to the through-thickness failure criterion, in obtaining data that is suitable for determining fatigue design S-N curves.

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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