It was only a matter of time. At the end of the vertical Nalgene smoosh, there were hints of more to come as I had unearthed another Nalgene of the same make (and with fewer stickers).
We learned from the previous experiment that, in a test of vertical compression, the threaded top failed at ~700 lbs and the main body lasted to ~1400 lbs before buckling. What sort of force could a horizontally oriented Nalgene cylinder resist? Arches and…circular things are supposed to be strong, right? “John” thought it could hold up to at least 3,000 lbf. This round we recorded the time-resolved applied load as the machine compressed at a rate of 0.5 in/min. The photo sequence below shows the Nalgene over time.
Once again, the main body failed at 1400 lbf! The inner shadows visible in b and c are, I think, the same indentations visible in the first photo of this post. For stability, we placed the Nalgene on a metal plate with a small groove (just visible in b above). These cut into the bottle (see below) but I don’t think affected the structural integrity.
The bottle mouth, hanging over the edge of the plate, bowed out as well.
After a certain amount of flattening and spreading-out, part of the bottle was hanging over the edge of the plate. Thus one side (left in photo below) was more compressed than the other (right), resulting in a wedge shape. You can also see the indentations where it hung over the edge. “John” informed me one of the plates can pivot a couple of degrees – hence the need for the use of a notched plate for stability – which likely also contributed to differential pressure applied across the bottle.
One of our concerns was the effect the two bolts securing the top plate might have on the test. It turned out not to be an issue. One of the bolts did come into contact with the top lip, but only caused a slight indentation. Disaster avoided!
This test was a little less dramatic than the first, with no cracks or crazy shapes, and we knew it was not going to shatter. The most surprising find was that major structural failure occurred under the same load of 1400 lbs. Unfortunately I am now all out of these Nalgene bottles. Experimentation over?