Corrosion pits with a conical shape are typically observed in hold frames in way of cargo holds of bulk carriers which carry coal and iron ore. The ratio of the diameter to the depth of the typical corrosion pits is in the range between 8–1 and 10–1 and its diameter might become up to 50mm. The evaluation of residual strength of members with large uneven pitting corrosion is difficult compared with that of members with general corrosion. Therefore, it is of crucial importance to develop a method for the evaluation of residual strength of pitted members. The purpose of the present study is to investigate the effect of pitting corrosion on the ultimate strength of steel plates under various loading conditions and explore a method for the evaluation of residual thickness of pitted plates. In the present study, a series of non-linear FE-analyses has been conducted with steel plates with a variety of random pit distributions under various loading conditions such as uni-axial compression, bi-axial compression, shear and combination of these. In these analyses, random pit distributions were calculated by the previously developed corrosion model. It has been shown that equivalent thickness loss, which is defined as thickness loss of uniformly corroded plates with the same ultimate strength as the randomly pitted plates, is smaller than or equal to 1.25 times the average thickness loss. It has been also revealed that the equivalent thickness loss for the ultimate strength under the above-mentioned loading conditions is smaller than average thickness loss at the minimum cross section, where the average thickness loss at the minimum cross section almost corresponds to the equivalent thickness loss for the tensile strength. Based on these findings, a method for the estimation of equivalent thickness loss of pitted plates has been discussed using the thickness diminution-DOP relationship, where DOP (Degree of Pitting Intensity) is defined as the ratio of the pitted surface area to the total surface area.
Skip Nav Destination
ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering
June 10–15, 2007
San Diego, California, USA
Conference Sponsors:
- Ocean, Offshore and Arctic Engineering Division
ISBN:
0-7918-4268-1
PROCEEDINGS PAPER
Visual Assessment of Corroded Condition of Plates With Pitting Corrosion Taking Into Account Residual Strength: In the Case of Webs of Hold Frames of Bulk Carriers
Tatsuro Nakai,
Tatsuro Nakai
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Search for other works by this author on:
Hisao Matsushita,
Hisao Matsushita
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Search for other works by this author on:
Norio Yamamoto
Norio Yamamoto
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Search for other works by this author on:
Tatsuro Nakai
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Hisao Matsushita
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Norio Yamamoto
Nippon Kaiji Kyokai, Chiba, Chiba, Japan
Paper No:
OMAE2007-29159, pp. 125-135; 11 pages
Published Online:
May 20, 2009
Citation
Nakai, T, Matsushita, H, & Yamamoto, N. "Visual Assessment of Corroded Condition of Plates With Pitting Corrosion Taking Into Account Residual Strength: In the Case of Webs of Hold Frames of Bulk Carriers." Proceedings of the ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. Volume 2: Structures, Safety and Reliability; Petroleum Technology Symposium. San Diego, California, USA. June 10–15, 2007. pp. 125-135. ASME. https://doi.org/10.1115/OMAE2007-29159
Download citation file:
16
Views
Related Proceedings Papers
Related Articles
Effects of Welding Residual Stresses on High Tensile Steel Plate Ultimate Strength: Nonlinear Finite Element Method Investigations
J. Offshore Mech. Arct. Eng (May,2012)
Modeling of Polymer Electrolyte Membrane Fuel Cell Stack End Plates
J. Fuel Cell Sci. Technol (November,2008)
Finite Element
Analysis of Plugging Failure in Steel Plates Struck by Blunt
Projectiles
J. Appl. Mech (September,2009)
Related Chapters
Strain Hardening and Tensile Properties
New Advanced High Strength Steels: Optimizing Properties
Repair Methods for Loadbearing Steel Structures Operating on the Norwegian Continental Shelf
Ageing and Life Extension of Offshore Facilities
Research on Strengthening Mechanism of Plant Root in Slope Protection
Geological Engineering: Proceedings of the 1 st International Conference (ICGE 2007)