The Ship Structure Committee launched a publication to develop and verify a design and performance evaluation method for crack arrestor enhanced aluminum marine structures.
Accordingly, ABS Consulting was tasked by the SSC to develop the following guide. The goal of this report is to enhance the existing modeling capability for crack initiation and propagation. This will efficiently and reliably capture the effect of a crack arrestor on the fatigue and fracture performance of a welded aluminum marine structure. Additionally, this improved capability will be used to explore an optimized design of a crack arrestor to achieve a design requirement.
The main objectives of the subject project are as follows:
- Investigate the state of the art with regard to crack propagation in aluminum, use of crack arrestor technologies to mitigate crack propagation in aluminum, and methodologies related to analysis and design of crack propagation in aluminum.
- Employ advanced analysis methodologies to study crack propagation and crack arrestor performance in aluminum marine structures.
- Conduct tradeoff study to evaluate influence of various factors on performance of crack arrestors in aluminum marine structures.
- Verify and validate modeling and analytical techniques against known performance (e.g. testing and other relevant published data) to affirm adequacy of modeling approaches.
- Prepare a comprehensive technical report summarizing all phases of work highlighting all assumptions and/or gaps in the body of knowledge.
This report summarizes the work performed under the above-mentioned tasks, the results obtained, and provides a detailed explanation of the methodology used to meet the project objectives.
In addition, the recommendations below are proposed:
- All the studied models are recommended to be tested in lab to revalidate the results and so that necessary calibration can be done.
- The proposed crack arrestors shall be considered “temporary repair“, but not the “permanent repair” (with an exception to type-4A), and it is recommended that the repaired locations are re-inspected / monitored periodically no more than an annual interval, until the permanent repairs (if warranted) are executed.
- Recommended to study additional modifications to the studied Crack Arrestors as follows those are addressed in Section 6.3.
Concluding, to learn more about the report, click herebelow
