scholarly journals Fatigue design of plated structures using structural hot spot stress approach

2012 ◽  
pp. 3146-3153
Author(s):  
M Heshmati ◽  
M Al-Emrani
Keyword(s):  
Hot Spot ◽  
Hot Spot Stress ◽  
Fatigue Design

Fatigue of Tubular Joints: Hot Spot Stress Method Revisited

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Pingsha Dong ◽  
Jeong K. Hong
Keyword(s):  
Hot Spot ◽  
Life Assessment ◽  
Structural Stress ◽  
T Joints ◽  
Hot Spot Stress ◽  
Tubular Joints ◽  
Fatigue Design ◽  
Fatigue Data ◽  
Section Viii ◽  
Remaining Life Assessment

A series of well-known tubular joints tested in UKSORP II have been re-evaluated using the mesh-insensitive structural stress method as a part of the on-going Battelle Structural Stress JIP efforts. In this report, the structural stress based analysis procedure is first presented for applications in tubular joints varying from simple T joints, double T Joints, YT joints with overlap, and K joints with various internal stiffening configurations. The structural stress based SCFs are then compared with those obtained using traditional surface extrapolation based hot spot stress methods. Their abilities in effectively correlating the fatigue data collected from these tubular joints are demonstrated. These tests are also compared with the T curve typically used for fatigue design of tubular joints as well as the structural stress based master S-N curve adopted by ASME Section VIII Div 2. Finally, some of the implications on fracture mechanics based remaining life assessment for tubular joints are discussed in light of the results obtained in this investigation.

Strategies for Fatigue Design of Deepwater Platforms

1988 ◽  
Vol 110 (2) ◽  
pp. 117-123
Author(s):  
P. W. Marshall
Keyword(s):  
Natural Frequency ◽  
Shape Parameter ◽  
Hot Spot ◽  
Wave Forces ◽  
Natural Period ◽  
Hot Spot Stress ◽  
Fatigue Design ◽  
Recent Developments

After reviewing strategies used for designing the 1000-ft Cognac platform, this paper will describe recent developments, which have been applied to preliminary designs of fixed platforms in up to 1600 ft of water, and to compliant towers in 2000 ft. The first is a strategy in which the waterline geometry and tower dimensions are coordinated so as to minimize wave forces at the natural frequency. This was first suggested by John Nath in 1967, and has come to be known as the “Nath hole” strategy [1]. The second is rationalization of allowable hot spot stress in terms of the Weibull shape parameter, “squiggly.” For structures which have been optimized as described in the foregoing, the trend of fatigue versus natural period can be much less severe than described by the author at the BOSS-82 conference [2].

Fatigue Strength Evaluation for Gas Welded Joint of Similar and Dissimilar Materials

2007 ◽  
Vol 345-346 ◽  
pp. 359-362
Author(s):  
Dong Ho Bae ◽  
Yeong Sin Kim ◽  
Gyu Young Lee ◽  
Kwang Jin Park
Keyword(s):  
Welded Joints ◽  
Welded Joint ◽  
Hot Spot ◽  
Tensile Load ◽  
Dissimilar Materials ◽  
Fatigue Tests ◽  
Design Criterion ◽  
Hot Spot Stress ◽  
Fatigue Design ◽  
Fatigue Design Criterion

In order to establish a reasonable and integrated fatigue design criterion for the long life design of the gas welded body structure, stress distribution around the gas welded joints subjected to tensile load was numerically analyzed. And also, the P-Nf curves were obtained by fatigue tests. By using these results, P-Nf curves were rearranged in the σ-Nf relation with the hot spot stress at the welded joint. And a guideline for fatigue design of gas welded joints was proposed.

Fatigue design using the structure stress concept for welded metal structures

2021 ◽  
Author(s):  
Niclas Rausch ◽  
Martin Mensinger
Keyword(s):  
Hot Spot ◽  
Local Stress ◽  
Correction Factors ◽  
Stress Determination ◽  
Hot Spot Stress ◽  
Static Tests ◽  
Metal Structures ◽  
Solution Strategies ◽  
Fatigue Design ◽  
Element Approach

<p>Due to the progress in FE calculations, local stress increases of welded metal structures can be evaluated more precisely using the structure stress approach (hot-spot stress concept). Inadequate regulations, however, lead to significant uncertainties with this approach. There is a deficiency in instructions on modelling, stress determination and methods for dealing with misalignment and thickness influences. Therefore, difficulties regarding the structure stress concept are pointed out and possible solution strategies are presented. To reduce uncertain influences from modelling, correction factors are specified based on the element approach, extrapolation rule and thickness. A series of static tests is carried out specifically for this purpose. The objective is to develop conclusive regulations for the hot-spot stress concept and evaluate it as an additional normatively anchored method for fatigue safety.</p>

Low Cycle Fatigue of T-Tubular Joints With In-Plane Bending Loading

2005 ◽  
Author(s):  
Jo̸rn Waalen ◽  
Stig Berge
Keyword(s):  
Low Cycle Fatigue ◽  
Hot Spot ◽  
Fatigue Loading ◽  
Hot Spot Stress ◽  
Tubular Joints ◽  
Fatigue Design ◽  
R Ratio ◽  
Plane Bending ◽  
Number Of Cycles ◽  
Bending Loading

Tubular T-joints were fatigue tested with in-plane bending loading. Six models were tested, three models with R-ratio of 0 and three with R = −1. Hot spot stress was measured for the brace and for the chord using the ECSC linear extrapolation procedure. Fatigue loading was applied in load control, to obtain through thickness cracking at a number of cycles in the range 3 000–64 000 cycles. The data were analysed and compared with the current fatigue design criteria for tubular joints.

Fatigue Strength Study on Different Structure Type of Hatch Corner

2011 ◽  
Vol 233-235 ◽  
pp. 2580-2583
Author(s):  
Yong He Xie ◽  
Wei Wang ◽  
Heng Zhang
Keyword(s):  
Fatigue Strength ◽  
Scale Effect ◽  
Hot Spot ◽  
Structure Type ◽  
Cumulative Damage ◽  
Hot Spot Stress ◽  
Fatigue Design ◽  
Miner’S Rule ◽  
Curve Method ◽  
Miner's Rule

The fatigue strength study of the hatch corner is carried out ,based on the S-N curve method and the assumption of the linear cumulative damage of Palmgren-Miner's rule, using the hot spot stress method. Study on the effect of the structure different type to the fatigue strength of the hatch corner is carried out through changing its construction details and thickness. By comparing, the reasonable structure is obtained, and the scale effect should be put into consideration in fatigue design.

Fatigue Design of Gas Welded Joint for the Railroad Car Body Using the Hot Spot Stress

2007 ◽  
Vol 353-358 ◽  
pp. 2806-2808
Author(s):  
Dong Ho Bae ◽  
Yeong Sin Kim ◽  
Gyu Young Lee
Keyword(s):  
Welded Joints ◽  
Welded Joint ◽  
Hot Spot ◽  
Tensile Load ◽  
Fatigue Tests ◽  
Design Criterion ◽  
Body Structure ◽  
Hot Spot Stress ◽  
Fatigue Design ◽  
Fatigue Design Criterion

In order to establish a reasonable and integrated fatigue design criterion for the long life design of the gas welded body structure, stress distribution around the gas welded joints subjected to tensile load was numerically analyzed. And also, the P-Nf curves were obtained by fatigue tests. By using these results, P-Nf curves were rearranged in the σ-Nf relation with the hot spot stress at the welded joint. And a guideline for fatigue design of gas welded joints was proposed.

Fatigue Strength Characteristics of Cast Steel Weld Joints

2011 ◽  
Author(s):  
Ho Jung Kim ◽  
Seong Min Kim ◽  
Jae Myung Lee ◽  
Myung Hyun Kim
Keyword(s):  
Fatigue Strength ◽  
Hot Spot ◽  
Cast Steel ◽  
Geometrical Parameters ◽  
Steel Weld ◽  
Hot Spot Stress ◽  
Butt Weld ◽  
Weld Joints ◽  
Fatigue Design ◽  
Notch Stress

The aim of the present paper is to investigate and compare the fatigue characteristics of weld joints in terms of S-N curve between cast steel and conventional mild steel. Two different joints such as thick butt weld joints and fillet weld joints are considered in this study. Fatigue strength of cast steel weld joints with various geometric designs are tested and compared. The fatigue life and the fatigue crack propagation characteristics are investigated by experimental and numerical methods in a systematic manner. The conventional hot spot stress, structural stress and notch stress approaches are employed for the precise interpretation of the fatigue test result of cast steel weld joints. Finally, the estimation of the fatigue limit of cast steel weld joints are attempted based on material properties and geometrical parameters. The results can be used for the efficient fatigue design of various cast steel welded joints.

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