the lurkist wrote:Is it plausible that the "soft" quality of the corbin sandstone actually acts as a buffer or shock absorber, allowing the bolt to fall back on its tensile qualities as it deforms down as the rock crushes under it?
I think it's a matter of how fast the bolt is loaded. A standard tensile or compression (and even Rick's testing and the UIAA testing) applies fairly slowly. This allows a material to slowly increase its strain until it first hits its yield point, then eventually its ultimate tensile/compression strength. In real life, we don't load bolts slowly; it's a VERY fast load. There is almost no time for a material to deform at its yield point as it is quickly strained to its ultimate(breaking) point.
Spoken like a wise metalurgical engineer.
One test we hope to do sometime is to drop a huge load off a cliff with a chain attached to a standard bolted hanger. That would be a worst case scenario for shock loading.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
3/8-16 rod is glued into a 7/16 hole (as opposed to a 1/2 hole, which is drilled for a 1/2-inch sleeve bols with a 3/8-16 bolt inside)
A variety of adhesives are being tried.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau
Huggybone wrote:I think Black diamond tested them years ago.
Sorry, I should have clarified "recently". I am sure they have held more than a few falls in there day, but they have been hanging out there a few years and I am curious about there quality.
"how ironic....now he's blind after a life of enjoying being able to see."~Homer
