What is snap-through buckling??? 2

[TimLiu1021]

Hi everyone.I need to do the project about steel dome structures.I read some paper and searched in the websites.I found that the snap-through buckling is common failure in shallow dome, but I don't understand snap-through buckling.Please explain what is snap-through buckling and why it is common failure in shallow dome to me.Thank you.

 

[dik]

Some shapes and materials go through a phase where the loading increases after initial buckling. This is the 'snap through point. It is comon with CFS sections.

http://enu.kz/repository/2011/AIAA-2011-2083.pdf

Dik

 

[JAE]

https://www.youtube.com/watch?v=5j1AIw3_M40

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[KootK]

For a fundamental understanding, I like the classic example of a system composed of two axially loaded bars loaded at the apex. While the apex remains above the horizontal, the compression in the bars resists buckling and the system is stable. As soon as the the apex drops a hair beneath the horizontal, however, the compression in the bars actually encourages buckling which takes place rapidly (the snap). The system eventually becomes stable again as the apex drops further and the bars go into tension. For most practical situations, however, the amount of displacement involved represents failure of the system.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[KootK]

This is the load/displacement curve for such a system under a displacement controlled testing setup. The dotted red line speaks to dik's point.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[klaus.]

Tim if you are a student doing a student project then I can understand your question
But if you are doing a real project I suggest that you get help of a professional engineer for that dome project
A very good knowledge on stability analysis and stability theory is required for designing sensitive steel domes





best regards
Klaus

 

[canwesteng]

Axial compressive load reduces the length of the members in compression, causing the angle of the truss to get shallower. The shallower angle results in larger axial forces. If the load-displacement curve diverges, the structure isn't stable until the apex "snaps-through" and puts the members in tension.