Dear all，

I would like to ask how to set the number of two members, because there are no examples of two members in the example, so I can not refer to.

Best regards

Dear all，

I would like to ask how to set the number of two members, because there are no examples of two members in the example, so I can not refer to.

Best regards

Dear @XinPei.Zhang,

Can you clarify why you want to use BeamDyn to model a beam with more than one member (element)? We generally recommend when using BeamDyn to model the beam with a single member/element and to use `order_elem`

to increase/decrease the precision of the model (by adding/removing degrees of freedom).

Best regards,

Dear Jason.Jonkman

I 'm simulating a cantilever beam bending into a circle under load, in ’ Nonlinear Legendre Spectral Finite Elements for Wind Turbine Blade Dynamics ’ mentioned the use of two fifth-order lsfe, in the process I tried to use a number of members to simulate, but the result is not correct, I do not know where I set the wrong, I am very confused about this. Here is my setup file, and the corresponding article, can you help me ? If this is a very simple matter, I am sorry for this and take up your precious time. I did this to verify that my beamdyn was working properly.

Dear @XinPei.Zhang,

You mention that you are using two 5th order elements, but I only see one member/element defined in your input file.

You mention that your results are not correct, but haven’t stated/shown what your results are.

Can you clarify?

Best regards,

Dear Jason.Jonkman

Thanks for your reply. Sorry, I didn’t express myself clearly enough. Below is my simulation file and validation article, I simulated the example on page 6 of the article, when λ=2, x1 and x3 are 0 and -10 respectively. Articles are measured in inches, while openfast is measured in meters. Therefore, the correct result for openfast should be 0, -0.234. But my results are -0.178, -0.13. The article points out that two fifth-order LSFEs are used, and I do not know how to set two members, so only set one to simulate, is this the reason why I made an error? Or is it because I set the parameters incorrectly? Could you please check it for me? Thank you for your kind advice during this time.

(Attachment beamdyn.pdf is missing)

(Attachment beamdyn.zip is missing)

Dear @XinPei.Zhang,

Are you results different for all values of the applied moment or only for lambda = 2? How do the results compare at lambda = 0.4?

Best regards

Dear Jason.Jonkman

Yes, my last email was about λ=2, and I also tried other λ values, but they were also wrong. For example, when λ=0.4, my simulation result was x1=-6.24E-05,x3=-4.87E-03. I don’t know if my stiffness matrix is set up correctly, or my load is set up wrong, or the calculation unit conversion is wrong. I’d like to try using 5 lsfe with two members, but I don’t know how to set it up. Can you give me some advice?

Best regards

Dear Jason.Jonkman

I found other articles on the forum, which mentioned that the initially twisted beam and cantilever beam adopted the same stiffness matrix, and the test example provided by openfast showed that the initially twisted beam was exactly the same as the article, and the operation results were accurate. Therefore, I replaced the initially twisted beam stiffness matrix with the original stiffness matrix of the cantilever beam, and ran λ=0.4 and λ=0.8, and the results were completely accurate. I’m so happy. But running λ=1.2, 1.6, 2.0 will report errors, can you give me some advice? I have a question, why is the stiffness matrix given in the article not applicable?Thank you so much. Have a great life.

Best Regards,

Dear @XinPei.Zhang,

I was not the one to run this test originally, and so, can’t comment on the beam properties.

I don’t actually see any errors in your screenshot. (The message about nodal outputs is a warning, not an error.) What happens after the `Time: 0 of 60 seconds.`

line is printed?

This section of the BeamDyn documentation explains how the BeamDyn input file should be formatted if you specify two elements: 4.2.4.3. Input Files — OpenFAST v3.5.1 documentation. But again, we generally recommend only using one element unless you have a step change in beam properties.

Best regards,

Dear Jason.Jonkman

Thanks for your help these days, I think I have learned how to use beamdyn, which I have been learning recently, successfully solved all the previous problems, and matched perfectly with the article examples.

Best regards,

1 Like

Dear @Muhammad.Irfan,

The first error regarding “locked” is self explanatory.

The second error regarding “syntax error” has been asked and answered in other forum topics, e.g., see: problem in running Test03 to Test25.

Best regards,

thanks Dear jason for explanation

Dear Jason.Jonkman

Can you give me some validation papers on running aerodyn alone? Thank you very much.

Best regards,

Dear @XinPei.Zhang,

I’m not sure I understand what you are asking for, but guidance for running the standalone driver for AeroDyn v15 is provided here: 4.2.1.6. AeroDyn Driver — OpenFAST v3.5.1 documentation.

The following *Wind Energy Science* article that makes use of the AeroDyn driver may also be of interest to you: WES - A multipurpose lifting-line flow solver for arbitrary wind energy concepts.

Best regards,

Dear Jason.Jonkman

Thank you. That’s what I wanted.“Wind Energy Science article”

Best regards，

Dear Jason.Jonkman

When I checked the simulation, I found that there was something wrong with one graph and nothing wrong with the others. The data simulated by beamdyn and HAWC2 are exactly the same, so I wonder whether the figure in this article has exchanged the data of beamdyn and HAWC2. Just a guess, and if it’s something else, I’m sorry about that. Can you give me some advice? The simulation example is ‘Case 4: Composite beam with a sinusoidal force applied at the free end’

Best regards,

Dear @XinPei.Zhang,

Are these results from the following paper?:

Pavese, C.; Wang, Q.; Kim, T.; Jonkman, J.; and Sprague, M. A. “HAWC2 and BeamDyn: Comparison Between Beam Structural Models for Aero-Servo-Elastic Frameworks.” *Scientific Proceedings European Wind Energy Association Annual Conference and Exhibition, 17–20 November 2015, Paris, France.* Brussels, Belgium: European Wind Energy Association, pp. 1193-1201; NREL/CP-5000-65115. Golden, CO: National Renewable Energy Laboratory.

Good question, but I’m not sure. I didn’t run these simulations myself and don’t have access to the raw data. I would suggest reaching out to the lead author.

Best regards,