Hi,

I defined an orthotropic ply (Et1=Ec1=141GPa, Et2=Ec2=9.34GPa, G12=4.5GPa) with the lamina strain allowables etu1=etu2=4500microstrain, ecu1=ecu2=3500microstrain, esu12=4500microstrain.

From this ply I create effective laminates, which I then use in a pre-design structural analysis. Therein, I use max strain criterion to evaluate the effective laminate strength.

For my understanding, using an effective laminate, you have no information about the number of plies or their stacking.

So, my question is: How do I calculate the effective laminate strain allowables from the ply values?

E.g. for a 50% 0°, 30% +-45° and 20% 90° effective laminate: Does HyperSizer built a discrete laminate internally to compute the A-Matrix and thus calculate the effective engineering constants? Does HyperSizer use such an internal discrete laminate for the determination of the effective laminate strain allowables, as mentioned in

this post for the stress allowables? If yes, which criterion is used for this analysis?

For the 50% 0°, 30% +-45° and 20% 90° effective laminate with the mentioned ply values I get etu1=10758.29microstrain; etu2=10952.44microstrain; ecu1=7190.529microstrain; ecu2=7358.728microstrain; esu12=12433.95.

I'd like to understand how I come to these values.