 # Small pitch distances in composite joints

SOURCE
The above URL contains the entire discussion. Below is a snippet.

QUESTION

I would like to know if there is a simple way of calculating the margin of safety of a composite joint due to a pitch distance considerable loss in a conservative way. As for example 2.5D or 3D pitch distances.

The reason is to calculate the margin of safety loss due to manufacturing discrepancies.
For example bearing bypass or the laminate resistance margins of safety.
I was wondering if a linear correlation could be valid. Imagine I have the bearing by pass margin of safety location in the structure. The design pitch is 5D. Due to a discrepancy the pitch is reduced to 3D. Can one calculate the new margin of safety based on a linear interpolation considering a zero margin of safety for 1D pitch, design margin of safety for 5D pitch and see where the 3D pitch would fall?

REPLIES

SWComposites
Assuming you are referring to fastener to fastener spacing as pitch, and not edge distance, I would conservatively assume zero strength (NOT zero margin) for pitch = 2D and linearly interpolate to that.