scholarly journals Compatibility of S-N and crack growth curves in the fatigue reliability assessment of a welded steel joint

2017 ◽  
Vol 5 ◽  
pp. 959-966
Author(s):  
Bahman Hashemi ◽  
Johan Maljaars ◽  
Davide Leonetti ◽  
H.H (Bert) Snijder
Keyword(s):  
Crack Growth ◽  
Reliability Assessment ◽  
Growth Curves ◽  
Fatigue Reliability ◽  
Welded Steel ◽  
Steel Joint

FATIGUE RELIABILITY ASSESSMENT OF WELDED JOINTS OF VERY FAST FERRY ACCOUNTING FOR VEHICLE LOADS

2021 ◽  
Vol 153 (A4) ◽  
Author(s):  
Y Garbatov ◽  
C Guedes Soares
Keyword(s):  
Hot Spots ◽  
Reliability Assessment ◽  
Stress Distributions ◽  
Structural System ◽  
Fatigue Reliability ◽  
Welded Steel ◽  
Longitudinal Stiffener ◽  
Hull Structure ◽  
Vehicle Loads ◽  
Wave Induced

This work deals with the fatigue reliability assessment of a welded joint in a longitudinal stiffener of trapezoidal shape in a very fast ferry. Based on the analysis of wave and cargo induced loads the ship hull structure is evaluated. The local structure is represented by a longitudinal stiffener with a trapezoidal transverse section. The critical hot-spots and the stress distributions are defined by FEM. The fatigue damage assessment of considered hot spots is analysed accounting for the combination of wave induced and car-breaking transient loadings. The formulation for the assessment of the welded steel joint is based on the S-N approach and FORM/SORM techniques are applied to evaluate the reliability against fatigue failure accounting for corrosion deterioration. The structural system composed by several hot spots is evaluated as a series system based on second order reliability bounds.

Time-variant fatigue reliability evaluation of riveted lap joint under stationary random loading

2020 ◽  
Vol 234 (4) ◽  
pp. 567-578
Author(s):  
Shan Jiang ◽  
Yan-Fu Li
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Closure ◽  
Growth Model ◽  
Reliability Assessment ◽  
Fatigue Reliability ◽  
Lap Joint ◽  
Random Loading ◽  
Crack Growth Model

This article focuses on the time-variant reliability assessment of riveted lap joint structure subjected to fatigue. A physics-based fatigue crack growth model that can take the crack closure into account is derived to calculate the crack length at different time under arbitrary loading. In addition, several uncertainties are quantified, including the material, initial crack size, and loading condition. The stationary random loading is a common service environment in practice, in which the stress range and stress ratio vary with constant statistical characteristics (the mean and standard deviation). The time-variant fatigue reliability of riveted lap joint under stationary random loading is assessed by introducing the outcrossing concept. The experimental data of 2024-T3 aluminum alloy riveted lap joint under constant amplitude loading are used to validate the physics-based fatigue crack growth model. It is verified that this proposed model can predict the fatigue life probability distribution with a reasonable accuracy. In addition, the simulation of riveted lap joint under stationary random loading is performed. The time-variant fatigue reliability is evaluated. The results with or without considering crack closures are also compared. It is noted that the results from the time-variant fatigue reliability assessment considering crack closure has higher reliability level.

Bayesian Updating in the Reliability Assessment of Maintained Floating Structures

2002 ◽  
Vol 124 (3) ◽  
pp. 139-145 ◽  
Author(s):  
Y. Garbatov ◽  
C. Guedes Soares
Keyword(s):  
Crack Initiation ◽  
Crack Growth ◽  
Bayesian Approach ◽  
Crack Detection ◽  
Probability Distributions ◽  
Reliability Assessment ◽  
Bayesian Updating ◽  
Time Dependent ◽  
Fatigue Reliability ◽  
Floating Structures

The present paper adopts a Bayesian approach to update some of the parameters of the probability distributions governing the reliability assessment of maintained floating structures. It is based on a time dependent fatigue reliability formulation presented earlier but the description of the time to crack initiation, crack growth law and probability of crack detection are updated using the information from the inspections. Its performance is demonstrated with a simulated example.

Evaluation of Fatigue Crack Growth Curves in Existing Codes and a Proposed Modification Based on Experimental Data of Cr-Ni-Mo-V Steel Welded Joints

2016 ◽  
Author(s):  
Yan-Nan Du ◽  
Ming-Liang Zhu ◽  
Fu-Zhen Xuan ◽  
Shan-Tung Tu
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Welded Joints ◽  
Growth Curves ◽  
Crack Growth Behavior ◽  
Fatigue Assessment ◽  
Crack Growth Model ◽  
Threshold Regime ◽  
Near Threshold

A comparison of currently available codes for assessment of fatigue crack growth, including ASME (America Society of Mechanical Engineers) SEC. XI, FKM (Forchungskuratorium Maschinenbau) guideline, WES (Japan Welding Engineering Society) 2805, BS7910 and JSME (The Japan Society of Mechanical Engineers), was carried out by paying attention to the suitability of application and the easiness to obtain the parameters, based on fatigue crack growth data of Cr-Ni-Mo-V steel welded joints. Results showed that fatigue crack growth curves provided by the FKM or WES were good choice when few inputs were at hand while the curves in the BS7910, JSME and ASME were recommended for precise estimation. It was indicated that the assessment of welded joints solely by fatigue crack growth behavior at base metal part and the assessment of fatigue crack growth for the aged condition by as-received one both resulted in non-conservativeness, albeit dependent on the range of stress ratios, R. A new bilinear form of fatigue crack growth model independent of R was developed based on transition point occurred in the near-threshold regime. This constituted the bilinear approach to fatigue assessment, and thus contributed to the optimization of fatigue assessment in the near-threshold regime.

Fatigue reliability assessment of an existing steel railroad bridge

2001 ◽  
Vol 23 (10) ◽  
pp. 1203-1211 ◽  
Author(s):  
Sang-Hyo Kim ◽  
Sang-Woo Lee ◽  
Ho-Seong Mha
Keyword(s):  
Reliability Assessment ◽  
Fatigue Reliability ◽  
Railroad Bridge
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