Just a comment on the part of the paper that presents high-speed thermal images of the knots near the breaking point.
Which are really neat! --and from which one can also
get an idea --irrespective of temperature-- of GEOMETRY
of the loaded knot (which might be surprisingly changed
from what one saw upon mere setting of the knot).
While the authors admit that it is inconclusive
if the momentary rise of temperature near the breaking moment
is the cause of the breaking ...
... it must do well to show were forces concentrate.
I.p., nb the
Fig.9 (interior ("O") loading) being so MUCH
a-glow, not concentrating feeling the burn in one spot.
I'll conjecture that the
Fig.9 "I" ("exterior", in my terms;
"on top" in some others')-loaded eased the load of the
SPart straight(er) through to nip eye legs and thereby
impede them from reciprocating around the SPart
--enough so for the 5%pt.s difference (which still saw
the knot stronger than others but for the "O" loading).
Mark & I have mused that the diameter (we put in terms
of # of enclosed strands) of the SPart's main U-turn will
affect strength; but here we must acknowledge that the
bunny ears ("double") Fig.8 though doing well in "O"
loading (by reasoning I give above, IMO), was not at
the top of the heap strongest! --and in other testing
we can see only close results to
single-eye Fig.8s(both > & <, I think).
Thanks for re-bringing up this interesting report!
--dl*
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