Can you calculate dimensions knowing the volume fraction is 0.2?

[drennon236]

I am going to model this in a FEM programme (COMSOL), and for computational reasons the symmetry is fully exploited. Picture 1 is a cubic lattice structure, its supposed to be a small part of a major repetitive structure. Picture 2 is picture 1 even further simplified (imagine picture 1 being 3x3x3 unit cells of picture 2). I have been told for this structure, I can calculate the dimensions based the volume fraction of 0.2. Does anyone know how to calculate the dimensions (width, thickness, lenght) of picture 2 knowing that the volume fraction is 0.2?

Picture 1

Picture 2

 

[GregLocock]

It's the volume of a cube - the volume of 8 little cubes. So for a unit cube with section thickness t

1^3-8*((1-t)/2)^3=vol_fraction=.2

t=.072



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?