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bracket_frequency.mph library example not showing frequency response for 4th and up mode.

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Hello,

For a subjetc at uni, I have a to verify the frequency response to a harmonic force of 10KPa (Rayleight damping force of alfa 1(s-1) et B= 1e-5) in X axis for the bracket example, point to study is the tip of the left arm of the bracket (1). I will need to verify that the modes 4th an 5th are reacting to this force at 308hz and 365hz. When I tried to set the study to verify the existance of this behavior I cannot get a clear view of the respone, I have augmented the number of eigenfrequencies up to 6, I have set the system to look values close to this range (330hz), I set the graph scale in steps of 1hz to improve resolution with no succes. It is strange that first day I used the program at laboratory I got the response. But next day, in other computer cannont get the same graph. what am I missing.? ](http://drive.google.com/file/d/1G5b8jPtUnmpKecUBBWYMPQqbAI5j5aPH/view?usp=share_link)

I found out, that improving meshing from coarse to thin, did not do any improvement in the values of the eigenfreqencies , so I have a good convergency since the begining for this model. So what else could be the problem? Also, for the professor he is getting RMS amplitudes of 0.038 while the model only gets to 0.0011 in the libray example (1st eigenfreqncy response reaction)


1 Reply Last Post 19 nov 2022, 04:58 GMT-5
Acculution ApS Certified Consultant

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Posted: 2 years ago 19 nov 2022, 04:58 GMT-5

You would need to upload the file.

-------------------
René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
You would need to upload the file.

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