Strain processing example

[akeeste]

This example demonstrates a workflow to process strain gauge data from tidal turbine blade testing. Functions are not being included in an MHKiT module because test set-up is too variable to make generic functions easily. For now the workflow will live in this example notebook.

Data / code from:
Budi Gunawan, Kim Haulenbeek, Mohammed Abdellatef, Richard Streit, Eli Lynn, Mike Willis, Darren Pendley, Damian Gallegos-Patterson, Vincent Neary, Martin Wosnik (2024)
Calibration Of Fiber Optic Rosette Sensors For Measuring Bending Moment On Tidal Turbine Blades
International Conference on Ocean Energy, Melbourne, Australia, September 17 – 19, 2024.

[hivanov-nrel]

Hi Adam, could you upload the images that are in the notebook? I think the files are missing in the repo.

[akeeste]

@hivanov-nrel I fixed the image links and pushed them to examples/data/strain

[hivanov-nrel]

Hi Adam, good job on creating this example, which is a great introduction to someone who is trying to process strain gauge data.

I only have a few remarks that may potentially help improve clarity:

• I'm not familiar with this type of setup, but one question that comes to mind is that you mentioned that the blade is attached to a thin-walled rectangular cube. In your calculations, you consider the cross section to be where the blade enters the cube. Usually, the cross section is taken at the strain gauges themselves, which would result in a simple hollow rectangle. Unless i'm misunderstanding the "thin-walled" part and the cross section is actually the same throughout?
• It would be nice to add an image that shows a profile view of how the blade is loaded in relation to gravity. This would help add more meaning to the results. Maybe also adding some text explaining how the load is applied in the context of the strain gauge (blade transfers load to box which is "x" distance away from strain gauge measurement). This would provide more context for why we see that kind of moment.
• One of the main challenges of working with strain gauge data is answering "does this make sense?". So beyond just processing the data, adding commentary to the results may help someone get into that kind of mindset and have a better understanding of how to go about interpreting their own data later.

[akeeste]

Hi Adam, good job on creating this example, which is a great introduction to someone who is trying to process strain gauge data.

I only have a few remarks that may potentially help improve clarity:

• I'm not familiar with this type of setup, but one question that comes to mind is that you mentioned that the blade is attached to a thin-walled rectangular cube. In your calculations, you consider the cross section to be where the blade enters the cube. Usually, the cross section is taken at the strain gauges themselves, which would result in a simple hollow rectangle. Unless i'm misunderstanding the "thin-walled" part and the cross section is actually the same throughout?
• It would be nice to add an image that shows a profile view of how the blade is loaded in relation to gravity. This would help add more meaning to the results. Maybe also adding some text explaining how the load is applied in the context of the strain gauge (blade transfers load to box which is "x" distance away from strain gauge measurement). This would provide more context for why we see that kind of moment.
• One of the main challenges of working with strain gauge data is answering "does this make sense?". So beyond just processing the data, adding commentary to the results may help someone get into that kind of mindset and have a better understanding of how to go about interpreting their own data later.

Thanks @hivanov-nrel. All good points. I'll pull in some higher level context from the test report to address your comments

[akeeste]

@hivanov-nrel I finished a few more updates providing greater context on the test set-up and details of the blade root geometry. I'm waiting for an okay to push certain figures. I'll comment when that is done and I can push the rest of the updates

[akeeste]

@hivanov-nrel The additional figures and context on experimental set-up are now pushed

[akeeste]

@hivanov-nrel the review comments were addressed so I'll merge this PR. If you any other questions come up, we can refine in a future PR.