## Plate Buckling coefficients

## Plate Buckling coefficients

(OP)

Hello everyone,

Does anyone know how can I obtain the equation of the buckling coefficients for a composite plate ?. I want to know the function of this kind of chart :

Does anyone know how can I obtain the equation of the buckling coefficients for a composite plate ?. I want to know the function of this kind of chart :

## RE: Plate Buckling coefficients

kc = ((a/mb ) + (mb/a))^2

## RE: Plate Buckling coefficients

DoD/NASA Advanced Composites Design Guide Table 2.2.2.I

## RE: Plate Buckling coefficients

I found some curves from ESDU 94006. But these are specifically for plates where small deflection theory is applicable, because of the effect of bifurcational buckling. Also the results are not a coefficient, but an actual buckling load calculated based on a computer script. The result shows that the behavior is similar. I would recommend reading this document if you can find it as it has some good theoretical discussion.

Keep em' Flying

//Fight Corrosion!

## RE: Plate Buckling coefficients

On the other hand, a composite laminate has at least 4 independent elastic constants that affect the stability solution (D11, D22, D12, D66). This is assuming the laminate is balanced, that bend-twist coupling is minor, and that the transverse shear stiffness does not affect the solution. In the event that the laminate is unsymmetric, the D* components are preferred.

So rather than use a chart that gives you a coefficient, you can solve for the following equation for composites. The simple case for uniaxial loading and all edges simply supported is in MIL-HDBK-17, CMH-17, and various other publications. If you were to solve this equation for an isotropic material, you would see that you will be able to back out the Kc values and they are identical to the chart you attached. That is actually how the charts are developed (backing out coefficients from the analytical solutions - if available).

Brian

www.espcomposites.com