Filtering results of a linear buckling analysis!

[Mertsi1340]

Hi,
I am doing a linear buckling of a structure which consists of shell and stiffener plate. I am interested in the modes where the maximum occurs in the stiffener paltes only but in order to reach a load multiplier value of 25 i need almost 550 modes. Going through all these results one by one and examining whether the max occurs in the shell or stiffeners is quite laborious.

I could put all the stiffeners in a "Named Selection" and scope the results to this named selection only but that still does not eliminate the need to go through all the results.

Is there a macro or commands snippet where I could achieve this goal? Can anyone suggest a way of solving this problem?

 

[Transient1]

Since linear buckling analyses are inherently under conservative, you could still have useful results if you perform a pre-stressed buckling analysis where you include a small horizontal load on the plate stiffener. (Experiment with the load and its effects, i.e. start at 1/1000th your operational load, then 1/100th, etc).

That load will artificially promote the buckling mode you are trying to look at.


Why are you trying to figure this out? If the rest of the structure would buckle before this stiffener plate, then why does it matter?

 

[Mertsi1340]

Thank you for the post.

My linear buckling model is pre-stressed and is based on a load case that the standard requires.

I am analyzing a duct system and according to the standard I am using the load multiplier (=alpha critical) for the shell plates in my case should be above 1.6 a condition which this structure meets (my lowest load multiplier is above 4). So I am not interested in modes where the max occurs in the shell plates.

As for the the stiffeners, the standard requires a minimum of 25 for the load multiplier. Since my model produces over 550 modes in order to reach a load multiplier of 25 and I do not want to check the modes where the max occured in the shell plates, I was hoping of a way to filter all the results where the max occurs in the shell plates and list only those (if any) where the max occurs in stiffener parts.

These stiffeners can foe example be put in a "named selection" and the results scoped to these parts only, but that does not help much since I have to manually check and see whether the max occurs in the stiffeners.

I hope I made sense and clarified the situation.