# Why does figure 2 and 6 deform differently from the other shapes?

I am doing a linear buckling analysis on all the structures you see below, they are subjected to compression load in the x-axis as indicated by the arrow. You can see all structures beside 2 and 6 deform differently from the rest. Do you guys know why that might be?

• Sorry, I don't understand the question. If you do a buckling analysis on six completely different structures, why should any of the buckled shapes be the same as each other? Also, if the graphs are relevant to the question, what do the labels on the X axis mean? Commented Jul 15, 2021 at 2:09
• Its called irreducible Bruillone zone and it is complicated, but here is an example picture: imgur.com/a/DGOfm44 , but just by looking at the geometry - do you see any reason why it might be buckling the way it does when they all are subjected to the same load. And here is a wikipedia entry that explains the x-axis if you have the time: en.wikipedia.org/wiki/Brillouin_zone Commented Jul 15, 2021 at 2:11
• And didn’t all your previous questions about these structures give you the information? Commented Jul 15, 2021 at 6:44
• Well, that explains what they are, but it doesn't explain why you think the buckling modes should be the same. FWIW I am very familiar with working with a 1-D version of this type of Fourier decomposition (called "cyclic symmetry") and I can't really imagine any use for a linear buckling analysis of one cell. So I'll pass on trying to answer the question! Commented Jul 15, 2021 at 14:17
• Could you please say more about performing linear buckling analysis of one cell? Its related to the work I am doing now where Bloch-Floquet boundary conditions are used to find global buckling, not only cell-periodic. Commented Jul 15, 2021 at 14:37