While I agree with adfergusson's recommendations (I particularly like Barbero and Kaw is also quite practical) you can find a bit of advice online at John Pilling's site at
(you can also try his stuff at
And you can also try
That EdX course also looks quite interesting (I've signed up to check it out—thanks adfergusson).
You can design in composite as you can in any material but to get good results you should account for manufacturing methods early. You must also try to account for weaknesses of composite laminates (if you use a laminate) compared with isotropic materials you may have used before. This is similar to designing a structure in wood rather than metal. The analogy of wood is apt as wood has grain and it is similar in some ways to the fibers in continuous fiber composites. (Short fiber reinforced plastics such as glass/Nylon or carbon/PEEK can approximate isotropic materials but you must be quite careful to account for their idiosyncrasies such as how different manufacturing methods may align the fibers to a greater or lesser extent. Sheet molding compound or bulk molding compound are very common for simple parts such as hatches. They are often press-formed and given an elevated-temperature cure at the same time.) Some specialised manufacturers use continuous-fiber/thermoplastic matrix material to hot-form shapes from sheets, which with careful allowance for fiber deformation can be very effective.
Polymer matrix composites can be quite compact but they often end up taking up more volume than either steel or aluminum. See manhole covers at
Glass manhole covers have been one of the great successes, being much more handleable (injuries are much reduced) and durable than even steel covers.
Because a composite laminate may be a bit thicker than a metal one it is often a lot less likely to buckle for a given strength. (For a simple plate buckling goes with thickness cubed and strength with either thickness (in-plane) or thickness squared (bending).)
As well as the general references above you could try more specialised marine ones such as Professor Vasconcellos at
or Eric Greene at
These have a lot of general engineering information which may be more applicable to the sorts of hatches and the like you seem interested in.
From your description you will almost certainly want to use a glass or carbon fiber reinforced polymer. While many options are available those are good starting points (if you want to be a bit green you might consider a natural fiber rather than glass but bear in mind that they are very vulnerable to moisture, a bit flexible even compared with glass (which is pretty flexible) and are mostly very weak fibers without much consistency of their mechanical properties). Also bear in mind that regulations about fire may well affect the choice of a polymer matrix a lot.
Any further information about your intended products (or the existing ones you make in metal) will get you much more relevant information.
