Workshop 08

Workshop 08#

Workshop 08 has two goals:

  1. Allow you to apply system reliability methods to a real engineering problem, and

  2. Do it in a flexible timeline and format, based on the requirements of your HOS Unit

Schedule, Deadlines and Format#

There are only a few things to keep in mind:

  1. You can submit the assignment digitally (email Robert) or on paper (in class on Tuesday or Friday).

  2. If you submit the assignment in class on Friday, Robert will immediately give it a quick review, ask a few questions, and finalize the grade/feedback in class (as long as the work is sufficient).

  3. You can start the assignment immediately, but must turn it in before the end of the Friday session, June 14 at 12:30.

You can choose whatever document format you like, as long as you provide the following structure and information:

  1. Group name, member names (include members in cc if submitting via email)

  2. Overview of assignment contents

  3. Brief summary of problem solved, methods used, quantitative results and bullet point list of discussion points and recommendation(s) for additional analysis (if any)

  4. Diagrams and equations to describe your case study, as applicable. Use previous workshops as an example for the type of information to include.

  5. Analysis results. Use previous workshops as an example for the type of information to include.

  6. Relevant code should be included as an appendix in the form of a zip file or Git repository (link)

Note that if you do this digitally, you can copy our “typical” README.md, Report.md, Analysis.ipynb file and folder structure. On the other hand, feel free to modify the report structure described above as needed to fit well within your design project report.

Floating and Submerged Tunnels#

Note

As you will not get a quantitative grade for this assignment, the primary goal is to get feedback on what you will eventually include in your design report.

The scope of your assignment is the system reliability analysis required for your design report. Think carefully about what criteria you will use to quantify risk (e.g., risk types covered in MUDE and/or serviceability/ultimate limit states), how you will define failure of the system and which components are most important to include (don’t make things over-complicated). Include a specific statement about the criteria you will use to check whether the system reliability calculated is sufficient, and how it was determined (be concise).

Marine Renewables#

Note

As you will not get a quantitative grade for this assignment, the primary goal is to get feedback on what you will eventually include in your design report.

The scope of your assignment is the system reliability analysis required for your design report. Think carefully about what criteria you will use to quantify risk (e.g., risk types covered in MUDE and/or serviceability/ultimate limit states), how you will define failure of the system and which components are most important to include (don’t make things over-complicated). Include a specific statement about the criteria you will use to check whether the system reliability calculated is sufficient, and how it was determined (be concise). Below is some additional information to help you set up a system reliability analysis.

Observations from industry indicate that for a given system with many floaters, 6 incidents per year is considered acceptable, where “incident” is defined as a situation where a floater is no longer able to produce energy and requires interventions by personnel and equipment to get it back on line.

Typical design requirements are:

  • platform failure under strong wind/wave conditions: 5.0 \(\cdot\) \(10^{-5}\) per hour

  • moorings failure due to fatigue: 1.7 \(\cdot\) \(10^{-5}\)

  • moorings failure under strong wind/wave conditions: 7.8 \(\cdot\) \(10^{-5}\)

For this assignment you only need to present the proposed system reliability analysis, which should be a useful exercise for explicitly defining the component reliability analyses and extreme value analyses that are required. For your report you should be able to re-use WS05 to complete a component reliability analysis of the platform; you will need to come up with your own limit-state functions for other mechanisms/components.

Dikes, Dams and Breakwaters#

Note

You will receive a grade, similar to that of WS02 and WS05, although the format can be different, as described above. The goal is to make this complementary to your other assignments, so discuss with Robert if you feel that what you are doing is not constructive.

Your assignment is to give a perspective on the various system reliability problems in the dike assignment you are working on. You can choose either your dike assignment that must be turned in, or the Case Study in the Friday lecture by Richard Jorrisen. Include a specific statement about the criteria you will use to check whether the system reliability calculated is sufficient, and how it was determined (be very concise, as it is a standard procedure).

Consider these three situations:

  1. Wind load from any direction and overtopping failure mechanism

  2. Internal erosion failure mechanism

  3. Macrostability failure mechanism

For each situation, include the following:

  1. The relevant random variables

  2. Relevant limit state function for each component

  3. Explanation for how each component reliability problem will be solved (no need to do it in this assignment)

  4. Simple diagram of system reliability that indicates the function of the structure and relationship to the loads; identify the random variables and limit state functions (you can use any type of system diagram)

  5. Identify where dependence may play a role in the system and explain why (be concise! Determine whether dependence would increase or decrease the calculated failure probability

Note: for some loading situations, the random variables should be included as part of the limit-state function/component, not as separate “components.”

Contents