Does anyone know what a basic specification for a composite material or structure would entail in the aerospace industry and also in the automotive industry. I’m thinking along the lines of cost, stiffness, temperature resistance etc etc. I realise it will vary from part to part depending on the application but I am looking for a very broad specification which is not product specific. Generic but at a high level.
It’s not so much the material proprieties or even processing method that is the main specification for airspace, because as you said the requirement will vary from part to part. Eg: A 787 wing section will need to be strong and light and will cost $100k’s and made from prepreg, an air vent nozzle for a Cessna does not need to be as strong, but light and very low cost as they are replaceable and were wet lam’ed.
The main driver is your quality management system (QMS). Can you make every part exactly the same every time, and prove it. Bodies such as the FAA and EASA will require you to have a builders “licence” and formal QMS such as AS9100 (aerospace version of ISO9001, the is an automotive version too). Part of this is managing your raw materials and suppliers to ensure constant quality into your factory, and their storage and use. For prepreg this means checking and recording the batch numbers, roll numbers, data logging they storage, clean room and autoclave cure cycle. Moulds need to be numbered and checked. Staff training records kept, plus they have to have their own QA stamps to “sign off” each step. The list goes on, I know this as I’m 80% through implementing AS9100 at my job.
Basically the old saying hold true: For any part there must be an equal or greater weight of the part in paper work.