flexural rigidity

Hi there,

I need help on how to calculate the flexural rigidity (D) of an orthotropic plate. For instance, if I have a composite plate that has 2 plies. Ply 1 has Young's modulus of E1 and E2 with Poison ratio of V12, whilst Ply 2 has 2E1 and 0.5E2 with 1.2*V12.

For isotropic plate, I can use D = Eh3/12(1-v2). However, how to determine D for a composite plate using smear method. This value of D is needed to calculate the deflection of the composite plate using w = 0.00416 qa4/D, where a is the width of the plate.

Thank you for any feedback.

Dear all,

Iam working in composite orthotropic laminates consists of many plies having different material properties in each ply. How to determine or calculate the flexural rigidity (D) of this laminate by transforming these composite into an isotropic model. The idea is that flexural rigidity of the orthotropic laminate is being smeared into a single isotropic formulation.

For instance: if I have three plies:

Ply1 : D1x and D1y

Ply2: D2x and D2y

Ply3: D3x and D3y