thin and thick-walled composite beams 1

[zahzah]

Dear,

I hope that you reply this problem.
What's the difference between thick-walled composite beam and thin-walled composite beam theories ?

 

[stimpee]

The inclusion of tranverse shear deformation is the "equivalent" of thin vs thick for shell theory.

Neglecting shear deformation in all but the thinnest composite laminates is a sure recipe for "disaster" in my opinion due to the huge gap between the in-plane moduli, and the interlaminar shear modulus of the composites.

Steve

 

[RPstress]

zahzah: is it possible that you actually mean thick-walled and thin-walled cylinders, rather than beams?? (The terms thick- and thin-walled are't *usually* used with beams.)

 

[Miper]

Stimpee is right. Aerospace designers, among others, have discovered that interlaminar shear problems in thick composite beams (and shells, as RPstress points out) are significant. In other words, the epoxy shear strength/modulus between the fiber layers needs special attention. It can't be ignored as in thin materials.