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Community Tip - When posting, your subject should be specific and summarize your question. Here are some additional tips on asking a great question. X

Structural Dynamics Example

ZA_10146017
4-Participant

Structural Dynamics Example

Dear colleagues!

 

Please help me with the difficulties I am having trying to repeat a very important example step by step.

I tried to do as much as possible myself.

Nevertheless, a number of questions turned out to be impossible for me to handle.

Since, apart from the context and previous calculations, the essence of the questions will not be clear, I am attaching the original MathCAD file, the PDF example file, as well as a .xls file for the calculations.

All questions are highlighted in red in the MathCAD file with references to the example’s pages.

I will be extremely grateful to everyone for any comments/advice/hints.

 

P.S. I’ve tried to contact the author of this work in different ways, but there was no answer.

1 ACCEPTED SOLUTION

Accepted Solutions

Hi,

Full sheet

Includes all the graphs of Example 5.

Cheers

Terry

View solution in original post

6 REPLIES 6

Hi,

Excellent reference.

 

I have answered your first two questions about the graph of total response and that of mass participation factor.

The rest may take some time.

Cheers

Terry

Hi,

I am stopping for the day as it is very late in my part of the world.

 

I have found a unit inconsistency at the top of the file and am working my way through the sheet because of the unit problem. 

This will take time.  I have enclosed the file so far.

You need to multiply k1 and k2 by gravity to get force/length spring units. and mass matrix should be by kg.

This gives the period and frequency values in the reference.

It also show why in your original sheet you are using a factor of 100 that is not necessary if you use consistent units.

Capture3.JPG

Capture.JPG

Capture4.jpg

Capture2.JPG

Cheers

Terry

 

Dear Terry,

 

Thank you very much!

I didn't want to bother anyone with these questions, but I just couldn't get any further.

I know about units and just forgot to change them before posting.
I will be grateful for any other advice and insight from you.

 

P.S. The reference is just great. I put a lot of time just trying to realize all of its concepts properly. 

I fixed the units.

But other questions (especially Example 5) are still impossible for me to solve.

Hi,

Full sheet

Includes all the graphs of Example 5.

Cheers

Terry

Dear Terry,

 

I cannot express my gratitude.

Thank you very much - you helped me a lot.

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