Equivalent solid carbon fiber sheet to replace aluminum plate?

[bradler]

I have an extruded aluminum plate ~12in x 18in in size that is subject mostly to compression parallel to the face in the long dimension. The outside faces of the plate are ~1/8in thick and the internal extrusions consist of ~1/8in thick ribs x 0.2in wide spaced 1in apart oriented in the long dimension or parallel to the compression loads. So overall thickness if ~0.5in. This plate has significant deflection or bowing in the middle when under load and ultimately cracked on one face.

I am looking to replace it with a carbon fiber plate that will be have significantly less deflection. I would love to use a poly honeycomb core carbon skinned sandwich panel but it does not seem feasible due to fastener issues, wet environment, and I can only find very thin skinned panels. So Im trying to decide if a solid plate of quasi pre-preg carbon will be stiffer than the extruded aluminum "panel"? Due to the dynamic loads on the pate (its a motor torque plate) and complicated shape of the extruded aluminum piece it seems very hard to model and calculate the forces involved. So I guess Im looking for opinions like "oh yah 1/4in solid quasi carbon should be way stiffer"

Thanks for any input!

 

[berkshire]

See if you can give a drawing of what you have now, and explain why, you cannot substitutute a solid thicker sheet of aluminum in place of the ribbed sheet.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor