scholarly journals Incorporating mesh-insensitive structural stress into the fatigue assessment procedure of common structural rules for bulk carriers

2015 ◽  
Vol 7 (1) ◽  
pp. 10-24 ◽  
Author(s):  
Seong-Min Kim ◽  
Myung-Hyun Kim
Keyword(s):  
Assessment Procedure ◽  
Structural Stress ◽  
Fatigue Assessment ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Common Structural Rules

Research on Some Issues related to Fatigue Assessment based on Latest IACS Harmonized CSR Amendments

2015 ◽  
Author(s):  
Wu Jiameng ◽  
Cai Shijian ◽  
Wang Weifei
Keyword(s):  
Structural Design ◽  
Fe Analysis ◽  
Fatigue Assessment ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Key Issues ◽  
Common Structural Rules ◽  
Oil Tankers ◽  
The Impact

The IACS Harmonized Common Structural Rules (CSR-H) for Bulk Carriers and Oil Tankers has been issued on 1st Jan 2014, and will enter into force on 1st July 2015 to supersede the current CSR version (CSR-BC or CSR-OT). The latest amendments to 01 Jan 2014 version of CSR-H give lots of significant modifications on fatigue assessment. The purpose of this study is to introduce the main changes for fatigue requirement in such amendments, and evaluate their rationality based on some detailed FE analysis for some key issues. Meanwhile, the impact on the structural design, especially on the scantlings, will be discussed as well as some proposal. Some typical bulk carriers and oil tankers are investigated.

Ramification Study on IACS Harmonized Common Structural Rules: Impact on Structural Design and Scantlings

2014 ◽  
Author(s):  
Wu Jiameng ◽  
Wang Gang ◽  
Cai Shijian
Keyword(s):  
Structural Design ◽  
Classification Rule ◽  
Design Parameters ◽  
Functional Requirements ◽  
Safety Level ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Common Structural Rules ◽  
Oil Tankers ◽  
New Criteria

The Harmonized Common Structural Rules (CSR-H) for Bulk Carriers and Oil Tankers has been issued on 1st Jan 2014, and will enter into force on 1st July 2015 to supersede the current two separate CSR versions, namely CSR-OT for Oil tankers and CSR-BC for bulk carriers. CSR-H aims at a consistent methodology harmonizing CSR-OT and CSR-BC, and establishes new criteria and requirements with the further aim of compliance with the IMO Goal Based Standard (GBS) where GBS functional requirements fall within Classification Rule scope. To maintain equivalent or higher safety level than current CSR, the rule developments within CSR-H are as a guideline aimed at scantling requirements that will be the same or higher for a given CSR vessel given the same ship design parameters and structural arrangement both globally and locally. The purpose of this study is to introduce the main changes from CSR to CSR-H, the new criteria set up for GBS compliance, and evaluate their impact on the structural design, especially on the scantlings. A carefully selected set of ten bulk carriers and eight oil tankers are investigated with the focus not only on the midship area but also on the foremost and aftmost cargo block areas as well. The typical critical areas affected by CSR-H due to fatigue or buckling criteria are identified, discussed and analyzed in detail. The impacts on scantlings and improvement suggestions for structural design based on CSR-H are further summarized and conclusions made.

scholarly journals Methods for Structural Stress Determination according to EN 13445-3 Annex NA – Comparison with other Codes for Unfired Pressure Vessels

2018 ◽  
Vol 165 ◽  
pp. 10003
Author(s):  
Ralf Trieglaff ◽  
Jürgen Rudolph ◽  
Martin Beckert ◽  
Daniel Friers
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Structural Stress ◽  
Stress Determination ◽  
User Friendliness ◽  
Fatigue Assessment ◽  
Shell Elements ◽  
European Working ◽  
The Status

The European Pressure Vessel Standard EN 13445 provides in its part 3 (Design) a simplified method (Clause 17) and a detailed method for fatigue assessment (Clause 18). Clause 18 “Detailed Assessment of Fatigue Life” is under revision within the framework of the European working group CEN/TC 54/WG 53 – Design methods with the aim of reaching a significant increase in user-friendliness and a clear guideline for the application. This paper is focused on the new informative annex NA ”Instructions for structural stress oriented finite elements analyses using brick and shell elements”. As an essential amendment for the practical user, the determination of structural stress ranges for fatigue assessment of welds is further specified in this new annex. Different application methods for the determination of structural stresses are explained in connection with the requirements for finite element models and analyses. This paper will give a short overview of the proposed approaches of structural stress determination in annex NA of the revised EN 13445-3. It will present the status of the approaches based on the results of fatigue analyses according to EN 13445-3 Clause 18 for different application examples. For verification purposes, the results of the approaches proposed in EN 13445-3 are compared with the results of other pressure vessel design codes for nuclear and non-nuclear application.

scholarly journals ANALYSIS OF CORROSION DEPTH PERCENTAGE ON THE INNER BOTTOM PLATES OF AGING BULK CARRIERS WITH AN AIM TO OPTIMIZE CORROSION MARGIN

Brodogradnja ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 81-95
Author(s):  
Špiro Ivošević ◽  
◽  
Nataša Kovač ◽  
Nikola Momčilović ◽  
Goran Vukelić ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Alternative Energy ◽  
Structural Integrity ◽  
Linear Models ◽  
Metal Plate ◽  
Fuel Oil ◽  
Corrosion Depth ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Simple Conversion

To ensure the better structural integrity and maximum safety of bulk carriers in the ship design phase, an appropriate corrosion margin is introduced by the classification societies, which should enable the exploitation of ships during the projected 25-year life cycle. The new Common Structural Rules introduce even higher corrosion margin value to ensure the structural integrity of the ship. This directly affects the increase in hull weight and thus the need for more total installed power and higher fuel consumption. Higher fuel consumption results in increased emissions which directly affects environmental pollution. For these reasons, efforts are being made to introduce alternative energy sources, cleaner fuel, ship weight reduction, and the overall economic efficiency of ships. Therefore, using experimental data collected on aging bulk carriers, the paper explores the corrosion margin reduction potential considering its impact on hull weight. Assuming that the corrosive processes occur after four years of operation, a linear model that describes the percentage of plate wear as a function of the as build-in the thickness of inner bottom plates (IBP) of fuel oil tanks (FOT) located on the double bottom of aging bulk carriers, is analyzed. Over the course of 25 years, the IBP segment was monitored on 36 different ships surveys. In this way, 520 input data describing the depth of corrosion were formed. At the same time, records were kept on the mean thickness of the original metal plate, which enabled systematization of the empirical database and grouping of measured values by intervals of original plate thicknesses, and simple conversion of corrosion depth into adequate percentage values. Depth corrosion percentages were represented by standard linear models known in the literature. Based on this analysis, representative numerical and graphical results were obtained. Conclusions from the paper can assist to optimize corrosion margin and the energy efficiency of future vessels.

Fatigue assessment procedure for old riveted road bridges

2018 ◽  
Vol 18 (4) ◽  
pp. 1259-1274 ◽  
Author(s):  
Mieszko Kużawa ◽  
Tomasz Kamiński ◽  
Jan Bień
Keyword(s):  
Assessment Procedure ◽  
Fatigue Assessment

scholarly journals The elasto-plastic Point Method to estimate fatigue lifetime of notched metallic materials under variable amplitude multiaxial fatigue loading

2019 ◽  
Vol 300 ◽  
pp. 13004
Author(s):  
Namiq Zuhair Faruq ◽  
Luca Susmel
Keyword(s):  
Biaxial Loading ◽  
Fatigue Loading ◽  
Medium Carbon Steel ◽  
Multiaxial Fatigue ◽  
Point Method ◽  
Assessment Procedure ◽  
Fatigue Lifetime ◽  
Fatigue Assessment ◽  
Variable Amplitude ◽  
Strain Components

The present paper deals with the formulation and implementation of a novel fatigue lifetime estimation technique suitable for designing notched components against multiaxial fatigue. This fatigue assessment procedure was devised by combining the Modified Manson-Coffin Curve Method and the Shear Strain-Maximum Variance Method with the elasto-plastic Point Method. The accuracy of the approach being proposed was checked against a large number of experimental results that were generated by testing notched cylindrical samples of medium-carbon steel En8. These tests were run under proportional/non-proportional constant/variable amplitude biaxial loading, with the effect of non-zero mean stresses and different frequencies between the axial and torsional stress/strain components being also investigated. The results from this validation exercise demonstrate that the novel multiaxial fatigue assessment methodology being proposed is highly accurate, with its systematic usage resulting in predictions falling within an error factor of 2. This remarkable level of accuracy is very promising especially in light of the fact that this approach can be applied by directly post-processing the results from elasto-plastic Finite Element (FE) models solved using commercial codes.

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