Learning Forum

[Naji Al-Abed]

Hello I obtained the natural frequencies and mode shapes of the galloping enrgy harvester on Ansys Workbench but I am unsure of how to obtain a suitable harmonic frequency response curve? I have tried harmonic resposne plotting in the range of natural frequencies, where I measured the deformation at different drag forces where the drag forces are calculated in a speed range of 0-8m/s, but thing is when the drag force changes so does the frequency. I am really stuck on how to plot something accurate. I have also placed the forces on the rectangular body at the end of the beam and on the beam( that is clamped). Any suggestions please?
Kind Regards,
Naji

[Erik Kostson]

Hi

See our courses in harmonic analysis for details on how to set that up and how to create a FRF.

As for the other question what is the drag force (is there a fluid flow past this device), and what do you mean when drag force changes so does the frequency? Also what is the excitation here (force), you are only showing the modal system, include harmonic. so many more facts so forum members can provide some feedback.

All the best

Erik

[Naji Al-Abed]

Hello everyone,

I hope this message finds you well. I am currently working on a galloping energy harvester simulation in Ansys Workbench and I've encountered a challenge regarding the creation of a suitable harmonic frequency response curve. I have already obtained the natural frequencies and mode shapes of the system, but I'm unsure about the correct approach to generate an accurate harmonic frequency response curve. 

I have attempted to apply drag forces both on the rectangular body and the clamped beam, but I'm struggling to grasp the relationship between the drag force, frequency changes, and the harmonic response.

I greatly appreciate any guidance, insights, or suggestions you can provide to help me overcome this hurdle. If there are any relevant courses or resources that you recommend for harmonic analysis in Ansys, I'm eager to learn more.

Thank you for taking the time to read my query. Your assistance will be invaluable in advancing my understanding and successfully completing this simulation.
Please find the attached images below of the drag forces applied on the harmonic response.

[Erik Kostson]

Hi

Hope this course helps - all the best

https://courses.ansys.com/index.php/courses/harmonic-response-analysis-in-ansys-mechanical/

[Naji Al-Abed]

Hello, I tried following the video but I am still not getting reasonable graphs. May someone please have a look and advise me on what to do? 

I am currently working on a galloping energy harvester simulation in Ansys Workbench and I've encountered a challenge regarding the creation of a suitable harmonic frequency response curve. I have already obtained the natural frequencies and mode shapes of the system, but I'm unsure about the correct approach to generate an accurate harmonic frequency response curve. I have tried harmonic resposne plotting in the range of natural frequencies, where I measured the deformation at different drag forces where the drag forces are calculated in a speed range of 0-8m/s, but thing is when the drag force changes so does the frequency

I have attempted to apply drag forces both on the rectangular body and the clamped beam, but I'm struggling to grasp the relationship between the drag force, frequency changes, and the harmonic response.