Solving flexural rigidity of a composite plate

[kaizen.moto]

Hi there,

I need help about how to solve the flexural rigidity (D) of a composite. For instance, if I have two plies of a plate each with different material properties, i.e. ply 1 has different Young modulus from ply 2. Therefore, how can I determine the value of the overall D of the plate.
How can I smear the D?

Example:

ply 1 has E1 = 200 MPa, E2 = 30 MPa and v = 0.2
ply 2 has E1 = 400 MPa, E2 = 40 MPa and v = 0.3

using the D = Eh / 12(1-v^2), how can I smear the two different properties into a single value of D?

Please let me know. Thanks

 

[Navin A S]

.The flexural rigidity of a composite is determined by smearing the properties of each ply using a rule-of-mixtures approach. In the example you have given, you can calculate the overall flexural rigidity (D) of the plate as follows: D = (E1*h1 + E2*h2)/(12*(1 - (v1^2 + v2^2)))where, h1 and h2 are the thickness of ply 1 and 2, respectively; v1 and v2 are the Poisson's ratio of ply 1 and 2, respectively. In your example, you can calculate the overall D as follows: D = (200 MPa*h1 + 400 MPa*h2)/(12*(1 - (0.2^2 + 0.3^2)))Hope this helps.