scholarly journals Strength assessment method of ice-class propeller under the design ice load condition

2019 ◽  
Vol 11 (1) ◽  
pp. 542-552 ◽  
Author(s):  
L.Y. Ye ◽  
C.Y. Guo ◽  
C. Wang ◽  
C.H. Wang ◽  
X. Chang
Keyword(s):  
Load Condition ◽  
Assessment Method ◽  
Strength Assessment ◽  
Ice Load

Assessment of Free Spanning Pipeline Strength

2013 ◽  
Vol 310 ◽  
pp. 194-197
Author(s):  
Hong Jun Zhu ◽  
Xing Qi ◽  
Yong Chuang Yang ◽  
Ming Yang Wang ◽  
Xiao Xu Liu ◽  
...  
Keyword(s):  
Yield Strength ◽  
Fatigue Failure ◽  
Assessment Method ◽  
Submarine Pipeline ◽  
Strength Assessment ◽  
Buckling Strength ◽  
Safety Design ◽  
Pipeline Failures

Submarine pipeline failures usually occur at free span part, and free spanning pipeline is easily induced vibration by vortex, which accelerates the fatigue failure of pipe. Therefore, it is necessary to assess the strength of free spanning pipeline at regular intervals. In this paper, considering the effects of VIV, resonance assessment and yield strength assessment as well as buckling strength assessment are enumerated. And an illustration is calculated to verify the reliability of assessment method. This research may provide a guide for safety design, installation and maintenance of submarine pipeline.

Study on the Wave Loads and Strength Assessment Method on Semi-Submersible Platform

2009 ◽  
Author(s):  
Hui Li ◽  
Huilong Ren ◽  
Tao Wei ◽  
Guoqing Feng
Keyword(s):  
Fatigue Strength ◽  
Assessment Method ◽  
Wave Method ◽  
Wave Loads ◽  
Strength Assessment ◽  
Buckling Strength ◽  
Comprehensive Comparison ◽  
Comparison Of The Results ◽  
Classification Society

In this paper, the wave loads of a semi-submersible platform is calculated by the deterministic design wave method and the stochastic design wave method based on the rules established by ABS and DNV classification society respectively. Then, the yielding strength, buckling strength and fatigue strength of important members are assessed according to these different rules. Through the comprehensive comparison of the results of wave loads and strength assessment, the differences between these rules are summarized. Then some significant suggestions are given.

Fitness for Purpose Assessment of Girth Weld Defect Based on In-Line Inspection

2016 ◽  
Vol 853 ◽  
pp. 524-528
Author(s):  
Jian Chen ◽  
Zheng Qiang Lei ◽  
Fu Xiang Wang ◽  
Ting Wang ◽  
Ming Fei Li
Keyword(s):  
Oil And Gas ◽  
Assessment Method ◽  
Assessment Procedure ◽  
Defect Characterization ◽  
Strong Impact ◽  
Plastic Collapse ◽  
Fitness For Purpose ◽  
Strength Assessment ◽  
Weld Defects ◽  
Weld Defect

The girth weld defect is one of the most common types of defects on oil and gas pipelines, which can have a strong impact on the operation safety. Several girth weld failure accidents have occurred on PetroChina’s pipelines in recent years. In this paper, PetroChina’s current work on inspection and fitness for purpose assessment of girth weld defects is summarized. The in-line inspection has been proved to be the best practice for oil and gas pipeline defect inspection, but there are still some technical issues such as defect characterization and parameter selection. Fitness for purpose assessment methods for girth weld defects include strength assessment method based on plastic collapse, FAD method based on both plastic collapse and fracture, simplified factor method and numerical analysis method based on finite element. It is critical to identify the actual type of defects detected in in-line inspection to select an appropriate assessment method. The identification of various loads and the selection of appropriate material parameters are also important issues in assessment procedure. The key techniques to be developed include defect characterization, load identification, assessment of defects on high grade steel pipes, reliability-based assessment, etc.

Fatigue Yield of Ship Structures

2009 ◽  
Author(s):  
Kalman Zˇiha ◽  
Branko Blagojevic´
Keyword(s):  
Fatigue Strength ◽  
Fatigue Damage ◽  
Fatigue Analysis ◽  
Assessment Method ◽  
Rule Based ◽  
Strength Assessment ◽  
Variable Amplitude ◽  
Damage Progression ◽  
Double Hull ◽  
Fatigue Endurance

The paper on the first place summarizes the fatigue yield approach as a cause-effect interaction between fatigue damage progression and fatigue endurance. Secondly it investigates the fatigue strength worsening on experimental S-N data and the load variability effects in shipbuilding. Next it applies the Classification Society’s rule-based procedure for fatigue analysis of ship’s structure that uses a simplified fatigue strength assessment method. The example elaborates fatigue yield effect on the seagoing operation of a double hull 47400 tdw tanker. At the end the paper recommends the procedure for assessment of ship lifetime shortening due to the fatigue yielding under constant and variable amplitude block loadings.

Interaction and Assessment of Multiple Local Wall Thinning Defects

2013 ◽  
Author(s):  
Jian Peng ◽  
Changyu Zhou ◽  
Qiao Dai
Keyword(s):  
Critical Stress ◽  
Safety Assessment ◽  
Load Condition ◽  
Assessment Method ◽  
Relative Depth ◽  
Finite Element Analyses ◽  
Pure Bending ◽  
Defect Assessment ◽  
Wall Thinning ◽  
Local Wall Thinning

The safety assessment of pipes with multiple local wall thinning defects (LWTs) is systematically investigated by finite element analyses (FEA) with special attention to the interaction of multiple LWTs. It is interesting that the arrangement of LWTs (axial arrangement and circumferential arrangement), the load condition (pure pressure, pure bending and complicated load) and the relative depth play important roles in the interaction of multiple LWTs. The effective stress area and critical stress can be used to explain their influences. Moreover, existing assessment methods of multiple LWTs in some defect assessment standards such as API 579/ASME FFS, ASME B31G, BS 7910 and GB 19624 are reviewed. It’s noticed that the influences of arrangement, load condition and relative depth are ignored in existing standard methods, but they can influence the assessment results significantly. In order to consider these issues, an improved assessment of multiple LWTs based on API 579/ASME FFS is proposed. This improved assessment method has considered the influences of arrangement, load condition and relative depth, and can give better results.

Study on the Residual Strength Assessment Method on Corroded Subsea Pipeline Based on Reference Stress Method

2009 ◽  
Author(s):  
Hui Li ◽  
Xiaobing Pan ◽  
Huilong Ren ◽  
Guoqing Feng
Keyword(s):  
Residual Strength ◽  
Assessment Method ◽  
Von Mises Stress ◽  
Strength Assessment ◽  
Subsea Pipeline ◽  
Reference Stress ◽  
Minimum Cross Section ◽  
Input Pressure ◽  
Von Mises ◽  
The Relationship

In this paper, the reference stress method is adopted in the residual strength assessment of corroded subsea pipeline. Through the monitoring of the von Mises stress σlocal in the minimum cross section, the relationship between the stress response and input pressure is found. Then, based on this relationship, a simple and effective method to assess the residual strength of corroded subsea pipeline is proposed. Through the comparison with experimental results, the accuracy and reliability of this method is confirmed.

Strength Assessment of Corroded Pipelines — Finite Element Simulations and Parametric Studies

2017 ◽  
Vol 17 (07) ◽  
pp. 1750069 ◽  
Author(s):  
Chanyalew Taye Belachew ◽  
Mokhtar Che Ismail ◽  
Saravanan Karuppanan
Keyword(s):  
Finite Element ◽  
Assessment Method ◽  
Assessment Methods ◽  
Mechanical Resistance ◽  
Safe Operation ◽  
Strength Assessment ◽  
Defect Assessment ◽  
Parametric Studies ◽  
Operation Cost ◽  
Test Database

Pipelines are one of the most efficient means for transporting hydrocarbons from one point to the other. However, there is a great risk of pipelines operation failure due to the detrimental effects of corrosion. At the point of corrosion, the pipe wall becomes thinner and loses its mechanical resistance. In such cases, reliable defect assessment methods are necessary to decide whether to resume continual operation or to shut down for maintenance or replacement. However, the available assessment methods are over-conservative, which enforce either unnecessary maintenance or premature replacement. Furthermore, the defect assessment methods should not only ensure safe operation, but also optimized operation cost. Therefore, a new assessment method was developed based on the nonlinear finite element (FE) analysis and a parametric study of geometric parameters related to the corrosion defect. The new method was validated with burst test database, which can predict the burst pressure of corroded pipelines with better accuracy and consistency.

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