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j_ung
Jun 4, 2010, 8:01 PM
Post #52 of 58
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vegastradguy wrote: j_ung wrote: Freakin' engineers...  youve been here long enough to know better- i'm calling troll! 
It was a plot to type "Freakin' engineers..." FTW.
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edge
Jun 4, 2010, 8:05 PM
Post #53 of 58
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Registered: Apr 14, 2003
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Seriously, why does the name matter? If the rope does happy goodness, then you could label it "Gertudizade" and it would still be the rope doing it's job. Why do you need to know more than that?
Keep in mind that I am an engineer by training, and I still don't give a rat's hiney.
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JimTitt
Jun 4, 2010, 8:17 PM
Post #54 of 58
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Sort of interesting what this wreck take place!
All we did was use the force curves from drop tests which saves all these maybe coefficients and perhaps Hookian laws.
From the force curves (since energy is the area under a force/displacement curve) you can easily work out exactly which proportion of the fall energy is converted in the belay device, belayers hand, top karabiner and in the rope.
And in all cases the rope is the major converter of fall energy into heat.
As usual if you use a good thick rope and never fall off youŽll be o.k!
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theguy
Jun 4, 2010, 9:54 PM
Post #55 of 58
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JimTitt wrote: Sort of interesting what this wreck take place!
Yes it is! Like they say, everyone has an opinion, and many of these people happily ignore the information provided by those who have done the actual data gathering, since it contradicts their preconceptions.
And Jay, after contributing to the wreck with his opinion that "some heat has been generated, but it is apparently small compared with the strain energy in the rope, as every model of impact force I've seen ignores the heat" then stands back and points to the wreck as if he were an innocent bystander.
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ptlong
Jun 4, 2010, 10:46 PM
Post #56 of 58
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theguy wrote: And Jay, after contributing to the wreck with his opinion that "some heat has been generated, but it is apparently small compared with the strain energy in the rope, as every model of impact force I've seen ignores the heat" then stands back and points to the wreck as if he were an innocent bystander.
If he really meant it then one could say he is innocent by virtue of ignorance. But it is very hard to believe that Jay has never encountered a damped rope model.
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jt512
Jun 5, 2010, 2:06 AM
Post #57 of 58
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ptlong wrote: theguy wrote: And Jay, after contributing to the wreck with his opinion that "some heat has been generated, but it is apparently small compared with the strain energy in the rope, as every model of impact force I've seen ignores the heat" then stands back and points to the wreck as if he were an innocent bystander. If he really meant it then one could say he is innocent by virtue of ignorance. But it is very hard to believe that Jay has never encountered a damped rope model.
Well, actually I haven't. I wasn't even aware that there was a paper on it English. Also, your contention that, were it not for the damping, Hooke's Law would be adequate was news to me.
I downloaded the paper you provided the link to. I'll eventually have a look at it, but it might not be for a couple of weeks.
Jay
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j_ung
Jun 6, 2010, 11:27 AM
Post #58 of 58
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edge wrote: Seriously, why does the name matter? If the rope does happy goodness, then you could label it "Gertudizade" and it would still be the rope doing it's job. Why do you need to know more than that? Keep in mind that I am an engineer by training, and I still don't give a rat's hiney.
All I want is to be correct when I tell people ropes convert energy, instead of wrong when I tell them that ropes absorb force. Other than that, I agree. TMI.
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