I did a 1 day composites course at the ImechE last week to brush up my stressing and design skills.
It was profoundly depressing - there doesn't appear to be anybody with a good model to allow composite primary structure to be accurately modelled, and everybody is still forced into huge redundancy factors (currently I use 2.25, as compared to 1.5 for metal structures). The new fabrication techniques all seem to produce less strong structures than hand-layup, whilst their advocates wouldn't even venture that these techniques would increase consistency of manufacture enough to reduce the certification redundancy factors.
Having said that, I' am a composites fan and a CAA design signatory - but I wouldn't venture to computer model a new design with any great degree of confidence.
The best guys in the business I know are Slingsby, Angus Fleming at Aviation Enterprises, and Bill Brooks at Pegasus Aviation - it might be worth contacting them.
However, if you do want to do a computer analysis on a new design - you will have to throw a lot of cash at it.
G