Talk Composites - The Forum for Advanced Composites

Strength calculations

http://www.talkcomposites.com/Topic31643.aspx

By SP250 - 1/14/2019 8:59:14 PM

I appreciate that you are the suppliers of the materials and not the design engineers who decide on the lay up necessary for a part to function properly.
But I need to make a mould and to laminate up a carbon fibre, or glass, or a combination of materials for a scale model aircraft undercarraige.

Can you point me in the right direction please to get the number of layers and weight of CF cloth to perform the undercarraige job and still be stiff enough with the correct flex to absorb the odd very hard landing and still perform the job?

I know the dimensions of the full size aircraft UC part and the model will be 50% scale, but just down sizing it by 50% will give a far over engineered UC - too stiff for the job as the model weight will be in the order of 15kg and full size is 200kg dry & without a pilot.

Thanks for any help you can give.

John
By Warren (Staff) - 1/17/2019 11:21:27 AM

That is still quite a big model at that weight.  It is hard to advise without knowing what kind of design you have for the under carriage.  A lot of light RC craft use a simple U shape undercarriage for the 2 main wheels relying on the flex of the two legs on landing to absorb the energy.   That style of design may not be that efficient for a heavier aircraft although you would in reality need a bit of experimentation to see what works the best.