You are reading a single comment by @Emyr and its replies.
Click here to read the full conversation.
-
Given this datasheet: https://www.aiplastics.com/media/amari/datasheets/Nylon-6%20Datasheet.pdf
Is there enough information to get the Modulus of Elasticity and Poisson ratio? There is a tensile modulus of elasticity, but the unit is MPa. and there's no mention of Poisson.
edit: google says 1 MPa = 1 N/mm^2... and typical poisson ratio for Nylon 6 is 0.42
I'm assuming that calculator is for a plate just supported at the edges, whereas my sheet will be bolted down to a rigid frame, so different calc needed? Taking advantage of the tensile strength to compensate for a lack of rigidity?
Emyr
Not an engineer, but I think you should be looking at this:
https://www.engineersedge.com/calculators/flat-plate-deflection.htm
The dimensions should be 700 x 550mm
HDPE has a tensile modulus of about 1200 and a poisson ratio of 0.46.
You'll probably want it to survive a sizable child standing on one foot in the center of a gap. Let's say a child's foot has a contact patch with a radius of roughly 30mm and at 50kg that would give (500N/(pi*30mm^2) 0.2N/mm2.
A sheet of 15mm thick would then give you a displacement of ~4mm, which sounds acceptable. But that sheet would weigh about 30kg, which is a bit much. If you reduce that weight to 20kg by making the weight 10mm you'd get a displacement of 15mm, not sure if it'll survive that and don't know how to tell. Perhaps tell your children not to climb on the trailer, you'd get away with a far thinner sheet.
These are static loads though, riding over rough roads will introduce all sorts of vibrations but I had switched to the design faculty by then so I don't have a clue.