Learning Forum

[Divya Giri]

Hello Everyone,

I have investigated the buckling behavior of bamboo culm (200cm in length) with cracks considering nonlinearity. The cracks of dimensions (length of 40cm, width of 0.2 cm, and depth of 0.5 cm) were modeled at the top, middle, and bottom parts of the bamboo culm.

Since bamboo is a slender member, it is expected to have a higher deformation in the middle during buckling analysis. This means the critical load for the model with a crack at the middle part should be the lowest than the crack at the top and bottom. In contrast, I got the result of critical load from buckling analysis having the biggest influence with a crack at the bottom. The critical load for the top crack was around 24 KN, for the middle crack around 20 KN, and for the bottom crack 18 KN. 

Is it possible that the crack is affecting more likely at the bottom during buckling analysis? 

Any guidance or help would be really appreciated.

Thank you in advance!

 

Best Regards,

Divya Giri 

 

 

[peteroznewman]

Hi Divya,

You should describe the boundary conditions used at the top and bottom since they have a large effect on the critical buckling load.

[Divya Giri]

Hi Peter, 

Euler Third's case that pivots the model on both ends and axial compressive load from the top defines the boundary conditions and loading where the structure is fixed on the bottom and vertical displacement is allowed at the top. 

I had also tried switching to remote displacement with just an edge of one end, but it does not alter the result. 

 

Best Regards,

Divya Giri