Deflection of fiberglass rods

Dear All,

I am involved in a rather unusual outdoor sculpture project.

The concept is to create a large assembly of 20+ feet high vertical fiberglass rods that sway with the wind but always return back to their (perfectly) vertical resting position if there is no wind.

What’s the best way to predict their deflection other than trying out different rods from let’s say 1-2 inches diameter? Is there a (not too complicated) way to calculate their deflection? Any guestimates of applicable rod diameters? Any application where I could plug in different diameters and lengths that would visualize the swaying of the rods?

Thank you for your help!

Erwin

A 1" rod 20ft long standing vertical is barely going to flex much with just wind etc. You might consider fglass tubes, they will be lighter and cheaper.

I would estimate a 12-15mm dia fibreglass tube with 2mm wall may be about right, all depends on how much flex you need, how long, durability etc. Is it a permanent sculpture?