[dvdkhlng]

Last time I read about that, the problem seemed to be buckling [1]. E.g. if you look at Euler's critical load [2] then the pressure that a slender column can withstand just depends on the aspect ratio of the column (imagine a vacuum airship that uses internal columns to withstand the air pressure). So scaling things up means, that the column's weight has to scale proportionally with total airship volume (and the (air) pressure is a constant anyways). See also these discussions here [3]. Disclaimer: I don't claim to understand any of this.

[1] https://en.wikipedia.org/wiki/Buckling

[2] https://en.wikipedia.org/wiki/Euler%27s_critical_load

[3] https://en.wikipedia.org/wiki/Vacuum_airship

[im3w1l]

I did check the wiki article on Vacuum airships before writing my initial comment, and they are talking about the buckling of a hollow sphere, not of a column - hence why Akhmeteli and Gavrilin suggest considering alternative structures.

But regarding your point that the columns would have to scale with volume you might be right about that. I was thinking that it should scale with the total force, but the bigger your structure the longer distance the force has to be transmitted. So yeah I think I got that one wrong.