08-28-2020, 08:50 PM
(This post was last modified: 08-28-2020, 09:28 PM by O_Stodieck.)

(08-28-2020, 08:16 PM)Admin Wrote: A few notes:

- If all the plies are 0, then why go through the CLT process? Just use the beam bending formula as you did for the isotropic and the modulus that runs along the 1.5m direction. In other words, I was expecting some simple hand calcs like before.

- For a more general composite, I don't think you want the D matrix terms in this case. Rather, you should use the d matrix values. The D term would be used in a scenario where anticlastic curvature is resisted (I attached a snip from my book).

- I didn't follow the python code all the way through, but remember D (and d) are "per width" stiffnesses so you need to adjust them by the width. This will flush out if you do the simple PL^3/(3EI) calculation as well.

Thanks - just to clarify:

1) You are right, the current example is trivial, but CLT is a general method that could be used for any laminate.

The simple hand calc results in deflections very close to CLT :

# Analytical (Bernoulli beam):

I = (1.25e-04*12)**3*0.15/12

F = 0.1

L = 1.5

E = 9.0e9

Zmax = F*L**3/(3*E*I)

Zmax = 0.296296

Now we have 3 results:

Mystran =0.03613559 m

CLT = 0.296250 m

Beam = 0.296296 m

2) Could you share the reference please? I'm not familiar with a d matrix.

3) adjustment for width is in the code, where the bending curvature of the beam is calculated from Ky = D^(-1) * [0, M/width,0]