## CTE calculation

## CTE calculation

(OP)

I am doing a similar task as WK95 is, learning to design with composites by hand and have a related question that I think warranted its own posting. I'm using Barbero's book and am in micromechanics having just read the thermal expansion section-you calculate the CTE properties of the laminate using properties of the fiber and matrix, which makes sense. I was surprised to see however that this calculation uses the tensile modulus of both constituents as part of the calculation. What physical mechanism of the modulus comes into play to affect CTE? With metal design I have not seen this, and doubt that there is a connection there but the laminates are a different animal of course. Can some one explain how the modulus affects thermal expansion, or point me to a source?

Thanks,

Bob

Thanks,

Bob

## RE: CTE calculation

In other words, the ply's CTE is going to be closer the CTE of the constituent with the higher elastic modulus. Thinks about it this way. If the matrix had nearly zero stiffness, then the ply CTE would be the same as the fiber's. The matrix would just be along for the ride. And vice versa.

Brian

www.espcomposites.com

## RE: CTE calculation

## RE: CTE calculation