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Tsuli
Nov 13, 2007, 1:33 PM
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Hey guys, this is my first post. Been gleaning info from this site for a while. Figured it was about time i gave something back to the climbing community and go some way to thanking all those guys and gals for putting up mad climbs.
I hail from Brisbane, Australia. I've just completed an Engineering Degree, majoring in Materials and Mechanical systems. I've been working for a consulting company for about a year now, we take care of:
- Mechanical Testing (weld analysis, tensile/bending/shear strength of materials.)
- Product Certification (ie. testing products such as ladders, fences, construction equipment.... etc.. to Australian Standards)
- Failure Analysis: Investigating why and how things failed.
- NDT: Non-destructive testing (finding crack initiation points etc......)
........ So what all the above means is that i've got wealth of equipment and experience at my fingertips to help test some climbing stuff. I was hoping that this forum could provide ideas for things that people wanted tested. Some quick thoughts:
- don't really want to retest new biners for load ratings, i've looked at the standards and they are pretty rigorous. They'll all come out higher than rated.
- Instead, i thought i could test biners that have been dropped, used for ages, exposed to heat..... etc.
- Webbing left out in the sun
- Old ropes used for rapping off FH's (don't laugh, we actually did this a few times cause we were pretty naive and figured no-one would put something in the wall that'd be unsafe to thread a rope through and Ab off.)
- Rock Anchors in different types of rocks, using different setting methods.
- Knots..... etc.
These are just a couple of ideas I'm throwing around. Would love to hear from you guys as to what you're after and how i can help. I haven't talked to work about this but they'll be cool with it.
Really excited to be in a position to use my degree in such an exciting arena.
Take it easy, don
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viciado
Nov 13, 2007, 3:38 PM
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microbarn
Nov 13, 2007, 8:20 PM
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viciado wrote: Rocksport Inc. 10901 Plantside Dr. Louisville, Kentucky 40241 (502) 266-5833 www.climbrocksport.com Indoor climbing gym
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Tsuli
Nov 14, 2007, 5:56 AM
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microbarn wrote: viciado wrote: Rocksport Inc. 10901 Plantside Dr. Louisville, Kentucky 40241 (502) 266-5833 www.climbrocksport.com Indoor climbing gym spam?
Could be. They reckon they've available for design and installation of RC walls or maybe its a job offer...... :)
On the myth/s side of things.
Microfracture: Possible only under extreme circumstances since fracture toughness of metals generally pretty good and impacts causing a crack large enough to fail would have to be huge and hence, not really a MICROcrack at all, unlike ceramics... etc. But testing (http://onrope1.com/Myth1.htm) has proven that its not really of concern, Maybe if you dropped a piece from +50m onto a hard surface you may want to consider replacing it. Anyways, best measure is to check for visible cracks, anything smaller should not initiate catastrophic failure.
Point Loading (biner 2 biner): Funny thing is, most people are right with what they're saying but they are arguing at right angles to each other. Yes the stress is increased due to a reduction in contact area. But... this is not really a concern since the strength of the Al Alloy/steel is sufficient. Maybe if you were to put the same force through a razor blade tip your biner would fail, but the #1 reason for no biner 2 biner love is non-locking biners unclipping each other.
That's all i got at the moment.........
(This post was edited by Tsuli on Nov 14, 2007, 5:58 AM)
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viciado
Nov 14, 2007, 10:41 AM
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Not spam... just a glitch.
Not sure how that happened, I was replying to another post about climbing in that area and received an error notice. I re-posted later after poking around on the site. This was one of the threads I looked at in the meantime.
Apologies if it was due to my ineptitude
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microbarn
Nov 14, 2007, 12:10 PM
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I agree with you on both topics, but evidently this isn't enough to convince others.
In any case, I am now curious as to what you are looking for from this thread. In your original post you laid out some good details on what you are looking to test. Are you looking for ideas on how to test these things? Are you looking for more ideas on what to test? Are you wondering what the 'community' feels is most important to test?
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omalavet
Nov 14, 2007, 12:58 PM
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Tsuli wrote: microbarn wrote: viciado wrote: Rocksport Inc. Point Loading (biner 2 biner): Funny thing is, most people are right with what they're saying but they are arguing at right angles to each other. Yes the stress is increased due to a reduction in contact area. But... this is not really a concern since the strength of the Al Alloy/steel is sufficient. Maybe if you were to put the same force through a razor blade tip your biner would fail, but the #1 reason for no biner 2 biner love is non-locking biners unclipping each other. That's all i got at the moment......... what about wenyou clip t the bolt hanger!!! that is bull.... the bolt hanger is nowrower...
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misanthropic_nihilist
Nov 14, 2007, 2:08 PM
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Here's an extensive one:
Determine an equation for the Young's Constant of 1 inch tubular webbing. There'd be a lot of variables:
-age of webbing
-UV exposure
-moisture content
-temperature
Webbing also exhibits a fair amount of creep, so you'd probably have to test elasticity at a given time after application of load.
It would be interesting to have this information for slacklining. Without E, you don't know how much tension a straight slackline is under (without a tensile force meter).
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microbarn
Nov 14, 2007, 2:08 PM
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omalavet wrote: Tsuli wrote: Point Loading (biner 2 biner): Funny thing is, most people are right with what they're saying but they are arguing at right angles to each other. Yes the stress is increased due to a reduction in contact area. But... this is not really a concern since the strength of the Al Alloy/steel is sufficient. Maybe if you were to put the same force through a razor blade tip your biner would fail, but the #1 reason for no biner 2 biner love is non-locking biners unclipping each other. That's all i got at the moment......... what about wenyou clip t the bolt hanger!!! that is bull.... the bolt hanger is nowrower...
judging by your quoting and spelling skills, I doubt you could compare a razor and a bolt hanger width.
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omalavet
Nov 14, 2007, 4:23 PM
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ok i now english do yo now spanish.... my first laguage is spanish... but anyway.... i sya biner to biner wont do anything and for does people that say it does i whant to now what they say about hangers... not razor blades you moron
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microbarn
Nov 14, 2007, 6:15 PM
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omalavet wrote: ok i now english do yo now spanish.... my first laguage is spanish... but anyway.... i sya biner to biner wont do anything and for does people that say it does i whant to now what they say about hangers... not razor blades you moron
ok, I think your answers are being discussed over in the thread I linked to before:
http://www.rockclimbing.com/...post=1721322#1721322
Overall though, the whole idea is false. Biner on biner is fine. Biner on hanger, biner on wires, biners on piton, etc. they are all fine.
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drfelatio
Nov 14, 2007, 6:44 PM
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I'd like to know more about weather effects on cordage.
A friend and I were thinking of using cord (7mm nylon, TechCord, etc.) instead of webbing for rap anchors. We were wondering how much the sheath would protect the core from UV and if that would translate into a longer lifespan than webbing.
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hotgemini
Nov 15, 2007, 10:08 AM
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Don,
Wow, you're timing is fortuitous.
I'm brisbane based and am doing a bit of bolting and rebolting work around the place. I'd be very interested in doing some pull-testing of bolts, as I suspect would Phil Box and BrotherColin (both also on this forum).
Firstly and relevant to a discussion on qurank.com would be pull testing of tru-bolt mechanical anchors at different installed torques, in both tension and shear.
Secondly would be building on Steve Hawkshaw's excellent thesis. His tests weren't ideal because of the small size of the test block and the high number of tests performed in each block. So I'd love to test some U bolts in larger blocks.
Thirdly I'd love to test placing some bolts as per the original bolts on sunburnt buttress on tibro. Which I believe means chemset 101 placed in the heat of the middle of the day to see if we can't replicate their mode of failure (very poor glue-rock bond).
In short, I think we should talk.
Adam
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fencipede
Nov 16, 2007, 8:00 PM
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I second the pull-testing of bolts option, both expansion and glue-in in various rock strengths, particularly some of the relative newcomers to the game like the Fixe Triplex.
It's been around for a few years, but I haven't seen any non-manufacturer related documentation.
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sed
Nov 16, 2007, 8:43 PM
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I think there is a real need for testing bolts. I'd like to see many major naming climbing and industrial bolts tested in a variety of rock types. The ratings for industrial anchors in high/med/low concrete just don't seem to duplicate well what they are being used for. I would also like to see this data longitudinally, that is, how does their strength diminish not only over time but over number of lead falls.
Or maybe I'm day dreaming.
Scott
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Tsuli
Nov 19, 2007, 11:25 AM
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misanthropic_nihilist wrote: Here's an extensive one: Determine an equation for the Young's Constant of 1 inch tubular webbing. There'd be a lot of variables: -age of webbing -UV exposure -moisture content -temperature Webbing also exhibits a fair amount of creep, so you'd probably have to test elasticity at a given time after application of load. It would be interesting to have this information for slacklining. Without E, you don't know how much tension a straight slackline is under (without a tensile force meter).
Don't quite know what you mean here. You mean the young's modulus. If i find that out, how will you use it to determine the load the slack is under? Definitely interested in this cause i bought a slack line last week and its lost a fair bit of stretch.
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Tsuli
Nov 19, 2007, 11:41 AM
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hotgemini wrote: Don, Wow, you're timing is fortuitous. I'm brisbane based and am doing a bit of bolting and rebolting work around the place. I'd be very interested in doing some pull-testing of bolts, as I suspect would Phil Box and BrotherColin (both also on this forum). Firstly and relevant to a discussion on qurank.com would be pull testing of tru-bolt mechanical anchors at different installed torques, in both tension and shear. Secondly would be building on Steve Hawkshaw's excellent thesis. His tests weren't ideal because of the small size of the test block and the high number of tests performed in each block. So I'd love to test some U bolts in larger blocks. Thirdly I'd love to test placing some bolts as per the original bolts on sunburnt buttress on tibro. Which I believe means chemset 101 placed in the heat of the middle of the day to see if we can't replicate their mode of failure (very poor glue-rock bond). In short, I think we should talk. Adam
Adam, definitely interested in catching up to discuss your ideas. Will send you a message with my email.
Pull testing bolts on the walls will be easy using the ram from work.
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Tsuli
Nov 19, 2007, 12:03 PM
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Alright - So its really good to hear the feedback.
It seems there are three main areas to look at.
1) Webbing
2) Knots
3) Bolts
I talked to work today and they were a bit against with the whole situation which caught me off guard. However, they have given me the opportunity to test the tensile strength of knots and webbing. There is even the possibility that i'll be able to take the hydraulic ram out to places like KP and Tibro for bolt testing on the wall.
The big thing they stressed is that i don't mention their name on the results. They also made sure i understood my possible legal obligations, ie. include a disclaimer with anything i publish.
Another thing they would like me to aim for is gauging the need for actual 'for pay' work that the company could pick up. So far i was thinking along the lines of testing the anchor attachment points at climbing gyms, my understanding is that they are generally done every 6 months.
Keep the ideas coming guys, looks like i could get some decent work done on this in the coming months.
don
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rgold
Nov 19, 2007, 2:05 PM
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Not to be a spoilsport here, but I think that the kinds of tests that we really need are drop tests, and they require equipment Don may not have access to.
In the relatively rare instances when we have results of both kinds of testing, there seem to be discrepancies that are best explained as artifacts of the loading method. Climbing loads, at least the big ones, are not slowly applied. And tensile strength can be very misleading, especially with materials that are capable, to varying degrees, of absorbing fall energy.
Even with slow-pull testing, the major problem has been that not enough trials have been performed to achieve reasonable statistical reliability. Performing many trials requires money, of course, for the stuff being broken, and Don's pro bono approach, which he is already discovering is not popular with his employer, will not be able to test big enough batches.
In addition to the batch-size problem are conditioning problems; one wants to avoid the confounding effects of temperature, humidity, and storage conditions, and here again the necessary equipment for insuring uniform samples may not be available.
This is not to say that Don might not be able, in some cases, to obtain provocative results that could act as a catalyst for more testing by a bigger organization with more resources. But this is probably the best we can hope for from a guy working on his own time and money limited support of his employer.
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billcoe_
Jan 8, 2008, 1:17 AM
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I think that although large sample sizes are excellent and better science. Even small samples can give you a better feel for the approximate ratings, and certainly increase our knowledge which is starting as unknown for some of these things: which can be hugely beneficial, especially as it applies to unknown rock strength.
Rich, can you give a feel for what a testing methodology for bolts in a cliff might look like?
Also, can you advise specifically what a reliable test fixture might look like in terms of materials and build?
Grrraccias!
Bill
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rgold
Jan 8, 2008, 2:47 AM
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Bill, I'm strictly a theory guy at best. You need a real engineer, which I most emphatically am not, to decide on actual testing protocols and designs.
See if you can get Dave Custer at MIT to respond. (I've heard he is hard to contact, but he is teaching his physics of climbing course this spring, I think.)
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