Material "creeping" properties

#1

Does anyone have any links to studies on the various material propensity to creep under constant load?

There are numerous raw strength studies online - plenty of YouTubes with standardized printed pieces being pulled apart to establish breaking stress/strain information.

What I’m looking for is a similar study that checks for long term creep under, say, 10% breaking load conditions. I think that the experiment is something like:

  1. Measure breaking load of standard test piece
  2. Re-load to 10% of that value - measure length
  3. Come back in a week - measure length

I race yachts and I find that HMWPE (Spectra, Dynema) sail halyards creep about 2" over 100ft in about an hour of loading. Which doesn’t sound much, but definitely affects sail trim. I have printed a few parts in Nylon and I’m finding that nuts and bolts don’t stay tight over time because the material squashes out of the way. Obviously I can fix this by not tightening the bolts up so much or using big washers, but when parts on a sailboat are loaded, they can be under load for hours or days. I’d like to find some “creepage” studies on various 3D filaments.

0 Likes