Which modulus to use?

[Aviator168]

When calculating the angular deflation a carbon/glass fiber tube, should the shear modulus be used? But the tube is wrapped with uni fabric in 45 degrees, using the shear modulus for the calculation does not seem to be right? Your thoughts?

 

[wsimpso1]

Calculate the shear modulus - Q66 - of your +/- 45 laminate and use that in the the usual T*L/(GJ). Op

The rigourous method is to automate in a program (Excel and Libre Calc both work) to build up [ABBD], put in your loads, solve for strain vector, and check the failure criteria and deflections from there.

Billski

 

[Aviator168]

Yeah. What a pain.

 

[wsimpso1]

Airplane design is complicated with homogenous isotropic materials, moving to even lighter directional stuff requires even more of you.