Composites Manufacturing

I get the impression that you have never worked in composites, so I recommend you look for diverse information in http://www.jeccomposites.com, JEC monopolizes all the latest and widest activities in this field.

How about telling us what you are making then i can apply 40 years of experience onto your project. Chances are what you want to do has been done before,

Currently, I am verifying characteristics of composites profiles that are available on the market to pick suitable candidates for specific parts like arms, body, covers. In that specific version, We are exploring how much we can do with prefabricates.

Unfortunately, producers have a bad habit of providing scares information about their materials or part performance. Usually limited only to fibre properties. In the pest case scenario general value of Young Modulus for the composite.

Since the project is challenging for material (high loads, vibrations, big structure, ... etc. - lots of really cool problems), most of the products failed in FEM. To test those produced by companies that are not willing or do not have data for properly done FEM of composites, I have to fill the gap.

Means ... I need to find a reliable source of materials properties. If you know the fibre and assume general epoxy matrix... Screening for profiles to buy and test physically in the lab should be possible.

BUT ... to reliably simulate Composites you need complete data. In other case, you may forget about orientation or Tsai-Wu (not even mention of Tsai-Hill).

Back to the subject ... I know what I have to do with my project. I have issue with access to input for FEM.

Do your best guess, with standard available materials

then test with physical parts,

Like we do in aerospace. Our materials were defined.

i made the molds for R& D to cycle research thru. Lots of molds

Real flight parts, skins and structures.

If the outer shell of the part is defined say an arm, then

and all else is lay-up layers and different resin materials inside

.

Going thermo plastic or thermoset?

Part shape may dictate lay-up structure

Check out carbon fibre guitars

how you try to verifying characteristics of composites profiles ?

That is exactly what I am doing right now.

I just had hope to do it better. Therfore, I ask for help with the only resource I am missing. More reliable FEM input.

Big Aerospace is able to buy a piece of everything and test all the profiles that are there for their properties. Start-up need to pick.

Producers of the profiles that we are interested in do not release information on the loads that their products are able to transfer.

You have 30 parts you want to check and budget for buying 3. What do you do? FEM and then pick the best fit. And then check if your FEM model fit within reasonable error to the destructive test.

In the end, you use what behavior you can reliably predict.

That what I meant.

I understand budget, we did small material test coupons scaled into actual test structures into production.

I would start with accepted standard materials on the first three.

And add plys as FEM dictates.

Do you have the part model ?

Skin and structure ?

a lay-up scheme?

Some companies provide drawings of cross-sections. Some only pictures. Lay-up scheme is something that you usually have to ask for, but yes.

The problem starts when you ask for things like "Intralaminar Shear Strength". That is the moment when seals people wide open their mouth.

http://www.composite-oracle.com

Page with simple database. 3 bases available for free without registration:

• Fiber Database
• Resin Database
• Foam Database

ADVANCED GENERAL AVIATION TRANSPORT EXPERIMENTS

https://www.niar.wichita.edu/agate/

Reports from Composites measurements conducted by

National Institute for Aviation Research on Wichita State Univ.

"900GPa" Composite Materials Database with Free Access

https://www.900gpa.com

Very promising (still growing) database that aggregate and standardise composite materials properties delivered by manufacturer.

Base includes:

• Resins
• Fibres
• Pre-pregs
• Dry Fabrics
• Cores

From the first that practically anyone first engages in evaluating composites, I think your frustrations are virtually inevitable. For example, we might entertain higher modulus carbon fiber for a particular specialized assembly, not truly weighing the prospective ramifications of the assumed improvement being derived primarily from increasing tensile strength at the expense or greater risk of exceeding the compressive strength of your intended member.

The only process which has ever truly served my own few objectives therefore, was to develop my own software for modeling and analysis.