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05-05.-2008, 02:26 PM
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#91 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
"jim beam" wrote:
> Tom Sherman wrote: >> "jim beam" wrote: >>> Tom Sherman wrote: >>>> "jim beam" wrote: >>>>> Tom Sherman wrote: >>>>>> "jim beam" wrote: >>>>>>> Tom Sherman wrote: >>>>>>>> "jim beam" wrote: >>>>>>>>> Tom Sherman wrote: >>>>>>>>>> "jim beam" wrote: >>>>>>>>>>> [...] >>>>>>>>>>> nothing like the mental deformation we see from so-called >>>>>>>>>>> "engineers" >>>>>>>>>> >>>>>>>>>> Well, they are not "so-called" if granted a PE by a licensing >>>>>>>>>> board. >>>>>>>>>> >>>>>>>>>> What is your professional registration? >>>>>>>>>> >>>>>>>>>>> when they doggedly try to justify their underinformed >>>>>>>>>>> misconceptions. >>>>>>>>>> >>>>>>>>>> No hint of resentment here, eh? >>>>>>>>>> >>>>>>>>> >>>>>>>>> refusing to address the "engineering" then tom? shouldn't be >>>>>>>>> too hard for a "professional" to do. unless they're a >>>>>>>>> lightweight of course. >>>>>>>> >>>>>>>> "jim" refuses to answer the question - does "he" have any >>>>>>>> professional registration? >>>>>>>> >>>>>>> >>>>>>> you want a sock puppet to answer? are you some kind of retard? >>>>>>> >>>>>>> discuss the engineering, s/n < 1:100 goddamned lightweight. >>>>>> >>>>>> "jim's" silence is deafening. >>>>>> >>>>> >>>>> goddamned hypocrite!!!!!!!! >>>>> >>>>> goddamned lightweight. >>>> >>>> Note "jim's" continued refusal to answer the question. >>>> >>> >>> are you some kind of retard? where will a "sock puppet" get any kind >>> of accreditation? muppet university? >>> >> Does the person with his hand up the sock puppet's posterior have any >> type of professional accreditation? > > the puppeteer needs no accreditation - all they need is the sock's consent. > So "jim" is still ducking the question. >>> and get back to the engineering tom. here, let me replace what you >>> snipped: >>> >>> "brinell hardness # = P/pi.D.t >>> >>> where P = indenter load, D = indenter ball diameter and t = depth of >>> impression." >>> >>> so, as an "engineer", where's your argument about load and indenter >>> depth? >>> >> With the material previously work hardened or not? One does not run >> repetitive hardness tests on the same area, no? > > look up meyer's law. then convince me that you've understood it. In the case of a forged hub, the Meyer hardness would not change with indention depth, since the material started out being work hardened. For a cast hub flange, the Meyer hardness would continually increase as the test load was increased due to the cold working of the material. >>> goddamned lightweight. >> >> Ooooh, the wit of your insult is scathing.  >> > > "insult" and "scathing"??? it's simple observation of fact! > > but i guess truth hurts. goddamned lightweight. Prove the existence of God then. -- Tom Sherman - Holstein-Friesland Bovinia The weather is here, wish you were beautiful |
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05-05.-2008, 10:03 PM
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#92 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
Tom Sherman wrote:
> "jim beam" wrote: >> Tom Sherman wrote: >>> "jim beam" wrote: >>>> Tom Sherman wrote: >>>>> "jim beam" wrote: >>>>>> Tom Sherman wrote: >>>>>>> "jim beam" wrote: >>>>>>>> Tom Sherman wrote: >>>>>>>>> "jim beam" wrote: >>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>> [...] >>>>>>>>>>>> nothing like the mental deformation we see from so-called >>>>>>>>>>>> "engineers" >>>>>>>>>>> >>>>>>>>>>> Well, they are not "so-called" if granted a PE by a licensing >>>>>>>>>>> board. >>>>>>>>>>> >>>>>>>>>>> What is your professional registration? >>>>>>>>>>> >>>>>>>>>>>> when they doggedly try to justify their underinformed >>>>>>>>>>>> misconceptions. >>>>>>>>>>> >>>>>>>>>>> No hint of resentment here, eh? >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> refusing to address the "engineering" then tom? shouldn't be >>>>>>>>>> too hard for a "professional" to do. unless they're a >>>>>>>>>> lightweight of course. >>>>>>>>> >>>>>>>>> "jim" refuses to answer the question - does "he" have any >>>>>>>>> professional registration? >>>>>>>>> >>>>>>>> >>>>>>>> you want a sock puppet to answer? are you some kind of retard? >>>>>>>> >>>>>>>> discuss the engineering, s/n < 1:100 goddamned lightweight. >>>>>>> >>>>>>> "jim's" silence is deafening. >>>>>>> >>>>>> >>>>>> goddamned hypocrite!!!!!!!! >>>>>> >>>>>> goddamned lightweight. >>>>> >>>>> Note "jim's" continued refusal to answer the question. >>>>> >>>> >>>> are you some kind of retard? where will a "sock puppet" get any >>>> kind of accreditation? muppet university? >>>> >>> Does the person with his hand up the sock puppet's posterior have any >>> type of professional accreditation? >> >> the puppeteer needs no accreditation - all they need is the sock's >> consent. >> > So "jim" is still ducking the question. ok, let me translate: "my privacy trumps your irritation". > >>>> and get back to the engineering tom. here, let me replace what you >>>> snipped: >>>> >>>> "brinell hardness # = P/pi.D.t >>>> >>>> where P = indenter load, D = indenter ball diameter and t = depth of >>>> impression." >>>> >>>> so, as an "engineer", where's your argument about load and indenter >>>> depth? >>>> >>> With the material previously work hardened or not? One does not run >>> repetitive hardness tests on the same area, no? >> >> look up meyer's law. then convince me that you've understood it. > > In the case of a forged hub, the Meyer hardness would not change with > indention depth, since the material started out being work hardened. For > a cast hub flange, the Meyer hardness would continually increase as the > test load was increased due to the cold working of the material. whoa - castings work harden but forgings don't??? wtf is it with you engineers? don't you guys /ever/ pay attention in class??? that's a classic right up there along with eliminating fatigue from a material with no endurance limit! > >>>> goddamned lightweight. >>> >>> Ooooh, the wit of your insult is scathing. >>> >> >> "insult" and "scathing"??? it's simple observation of fact! >> >> but i guess truth hurts. goddamned lightweight. > > Prove the existence of God then. > you want a sock puppet to do that? come on tom, that's too lightweight, even for you. |
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05-05.-2008, 10:05 PM
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#93 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
Tom Sherman wrote:
> "jim beam" wrote: >> Tom Sherman wrote: >>> "jim beam" wrote: >>>> Tom Sherman wrote: >>>>> "jim beam" wrote: >>>>>> Tom Sherman wrote: >>>>>>> "jim beam" wrote: >>>>>>>> Tom Sherman wrote: >>>>>>>>> "jim beam" wrote: >>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>> Ben C wrote: >>>>>>>>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote: >>>>>>>>>>>>>> jobst.brandt@stanfordalumni.org wrote: >>>>>>>>>>>>>>> Stress relief. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I think deformation of flange holes in aluminum hubs is >>>>>>>>>>>>>>> being >>>>>>>>>>>>>>> mis-characterized, leading to incorrect assumptions about >>>>>>>>>>>>>>> effective >>>>>>>>>>>>>>> spoke hole position before and after stress relieving and >>>>>>>>>>>>>>> that >>>>>>>>>>>>>>> trueness of the wheel suffers from the process. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Hole deformation is an asymptotic effect that with >>>>>>>>>>>>>>> reasonable spoke >>>>>>>>>>>>>>> tension is already as deep as it will get. If that were >>>>>>>>>>>>>>> not so, >>>>>>>>>>>>>>> spokes would gradually sink through the flange and pull >>>>>>>>>>>>>>> out. Once >>>>>>>>>>>>>>> about a third of the spoke diameter bears fully on the >>>>>>>>>>>>>>> flange hole it >>>>>>>>>>>>>>> is as deep as it will go while subsequent stress relief >>>>>>>>>>>>>>> cannot "bed >>>>>>>>>>>>>>> them in" any deeper as the process is often depicted >>>>>>>>>>>>>>> here. The terms >>>>>>>>>>>>>>> bedding in or stabilizing are a misnomers chosen by >>>>>>>>>>>>>>> people who cannot >>>>>>>>>>>>>>> visualize mechanical stress relief or that spokes bed in >>>>>>>>>>>>>>> naturally >>>>>>>>>>>>>>> from initial spoke tension. >>>>>>>>>>>>>> The Rockwell hardness test (B scale, used for materials >>>>>>>>>>>>>> like aluminum) uses a 1/16" (1.6mm) steel ball and >>>>>>>>>>>>>> measures the depth indented with 100kgf. Typical hardness >>>>>>>>>>>>>> numbers for aluminum would indicate a depth of around >>>>>>>>>>>>>> 0.14mm (into a flat surface of reasonable thickness). >>>>>>>>>>>>>> While the scenario is a bit different, the dimensions and >>>>>>>>>>>>>> forces are similar. Given that the spoke and hole >>>>>>>>>>>>>> diameters are close and the angle is small, it seems that >>>>>>>>>>>>>> the absolute "bedding in" is small and happens early (with >>>>>>>>>>>>>> tension). From there it seems safe to assume that stress >>>>>>>>>>>>>> relief doesn't cause any significant additional "bedding in". >>>>>>>>>>>>>> >>>>>>>>>>>>>> Perhaps this issue is finally put to bed. >>>>>>>>>>>>> >>>>>>>>>>>>> I'm not quite ready to put it to bed yet. >>>>>>>>>>>>> >>>>>>>>>>>>> The most likely explanation in my mind is that during >>>>>>>>>>>>> stabilization the >>>>>>>>>>>>> spoke cuts into a new part of the hub flange (the outside >>>>>>>>>>>>> edge of the >>>>>>>>>>>>> hole probably) that it wasn't quite bearing on before. The >>>>>>>>>>>>> parts it's >>>>>>>>>>>>> already been pulled against by tensioning don't deform any >>>>>>>>>>>>> further for >>>>>>>>>>>>> the reasons you state. >>>>>>>>>>>> >>>>>>>>>>>> this is /so/ basic. if you increase the force, you get a >>>>>>>>>>>> bigger >>>>>>>>>>>> indentation. all you have to do is look at the formula: >>>>>>>>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...] >>>>>>>>>>>> >>>>>>>>>>> Does not the area deformed during initial tensioning work >>>>>>>>>>> harden, and would that not reduce the deformation from spoke >>>>>>>>>>> squeezing? >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> why do you think hardness numbers are comparatively, not >>>>>>>>>> quantitatively correlated with strength? >>>>>>>>>> >>>>>>>>> For different materials obviously, but for the same material? >>>>>>>>> >>>>>>>> >>>>>>>> oh dear, another "engineer" unclear on the concept. i'll ask >>>>>>>> again, "why do you think hardness numbers are comparatively, not >>>>>>>> quantitatively correlated with strength?". >>>>>>>> >>>>>>> That is irrelevant to the question at hand. In either case, work >>>>>>> hardening of the hub flange at the spoke holes will reduce the >>>>>>> amount of plastic deformation for a given future applied load, no? >>>>>> >>>>>> of course yes, but if you're unclear on the concept, and if you >>>>>> can't read the math, then you're a goddamned lightweight if you >>>>>> think it's not part of the hardness numbers!!! >>>>>> >>>>> Again, "jim" is introducing things tangential to the discussion at >>>>> hand. >>>> >>>> eh? the math and theory behind hardness tester indentation is >>>> "tangential" to spoke hole indentation??? what a goddamned >>>> lightweight!!! >>> >>> Well, valid hardness tests are NOT performed on an area that has >>> already been tested, and we were discussing additional deformation of >>> an area of the spoke flange during spoke squeezing that was already >>> deformed during tensioning. >> >> j.h.c. "valid" vs. "what" exactly tom??? or are you trying to be dense? >> > Valid versus invalid. Duh. says the guy that doesn't understand work hardening! > >> you've had a chance to do the math. you've had a chance to read the >> cites. now, you tell me, if you have a rockwell hardness tester, >> under "x" load it gives a reading, then, if you increase the load to >> "x+1", same indentation, no withdrawal, are you telling me the >> indenter will not sink further???? >> > Of course it will indent further, but not as far as if the test was > performed on a non work-hardened area. dude, you are /hopelessly/ confused. /any/ indentation is subject to work hardening. casting or forging. period. [and no hubs are cast btw.] work hardening is not a step function. > >>>>>>>> goddamned lightweight. >>>>>>> >>>>>>> You have keyboard macro's for insults? >>>>>>> >>>>>> >>>>>> no, it's lovingly typed out by hand, just for you. and it's an >>>>>> observation of fact. goddamned lightweight. >>>>> >>>>> "How to Win Friends and Influence People" - revised and updated by >>>>> "jim beam". >>>>> >>>> >>>> ask me if i give a flying one about the friendship and influence of >>>> goddamned lightweights! >>> >>> Yep, only because you hide behind a sock puppet. You would not be so >>> free with the insults if you had to use your real name, eh? >>> >> >> if i were a lightweight like "tom sherman", i sure wouldn't use a real >> name, that's for dead cretian! >> > What does "cretian" mean? > it's a more clinical form of "lightweight". |
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06-05.-2008, 01:01 AM
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#94 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
daveornee wrote:
> I don't have the explanations, but I am not against learning how to > correlate observations with sound engineering explanations. One > correlation you can help me with is the .75 mm you used earlier in this > thread and now the .14 mm. > I understand the concept of asymptotic function and agree that there > must be some point where the spokes approach it in normal operations. > I would like an explanation of "what gives" when I stabilize a wheel. I > build wheels to an even 100 kgf front and left rear. I then stabilize > the wheel be side loading until the spokes go to 150 kgf. When I do > this the front wheel needs 1/2 turn of the spokes to return to 100 kgf, > while the same applies to the right rear, the left rear needs 3/4 turn. > If all of the final adjustment were going to compensate for further > bedding in, the further bedding would be ~.225 mm front and right rear > and ~.38 mm left rear. > If I can't attribute any or all of the "final adjustment" to bedding > in, where would you attribute it to? Sorry to have taken so long to respond, but I've been trying to reason this out, especially in the light of your experiences, which admittedly are well beyond mine in terms of wheels built. I took some measurements on a Shimano hub (rear LX). I measured a flange thickness at the hole of about 4mm. The holes are parallel to the axle. The holes are countersunk about 1mm. The inside diameter seems about 2.8mm. This is my (current) best guess about what happens when you tighten & overload a spoke: The spoke head is conical, so is self-centering in the countersink. In that position, loaded with tension, it will resist rotation and translation. With these assumptions, the part of the spoke between the elbow and head can be considered to be a cantilevered beam of round cross section, 2mm in diameter, ~3mm long, centered in a 2.8mm bore. When the spoke is first laced, it's likely that it is not centered. For a left rear spoke, I'd guess that the first 1/3 tension centers the head, the next 1/3 tension bends the shank down to contact the bore, and the final 1/3 tension deforms the bore. Each of these represents about 0.4mm of movement. This gives 0.4mm depth of deformation at the bore edge. Front and right rear spokes go through the same movements, but the additional 50kgf of tension deforms the bore edge another ~0.225mm. This explanation assumes that the first 35kgf of additional tension after the spoke contacts the bore edge causes ~0.4mm of deformation, while the next 50kgf only an additional ~0.225. I think these numbers are reasonable because: The Rockwell hardness test for aluminum uses a 1.6mm ball with 100kg load. A typical "penetration" is 0.14mm. The Rockwell test is designed to operate in a reasonably linear region -- each "point" of hardness corresponds to a certain depth increment. I think the geometry of the spoke-on-bore loading is different enough to explain 0.14/100 to 0.4/35 (~8:1 vs. Rockwell) and 0.225/50 (3:1) differences. The spoke-to-bore interface initially is cylinder to edge because the cylinder makes a small angle (~5 deg) to the bore axis. This means that the way the contact patch grows with deformation is very different than the Rockwell ball on flat surface. I think this explains both the much higher initial "penetrability" as well as the much greater non-linearity. I haven't done the math to compute the volume/depth of the contact patch, but I think the non-linearity is intuitively visible since the contact patch both grows rapidly in area and grows back from the unsupported edge. I'm assuming (for the context of your numbers) something like 70kgf initial tension for left-rear, 100kgf front and right-rear, followed by 105kgf left-rear and 150kgf front and right-rear peak during stress relief. |
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06-05.-2008, 01:00 PM
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#95 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
Peter Cole wrote:
> daveornee wrote: > >> I don't have the explanations, but I am not against learning how to >> correlate observations with sound engineering explanations. One >> correlation you can help me with is the .75 mm you used earlier in this >> thread and now the .14 mm. >> I understand the concept of asymptotic function and agree that there >> must be some point where the spokes approach it in normal operations. >> I would like an explanation of "what gives" when I stabilize a wheel. I >> build wheels to an even 100 kgf front and left rear. I then stabilize >> the wheel be side loading until the spokes go to 150 kgf. When I do >> this the front wheel needs 1/2 turn of the spokes to return to 100 kgf, >> while the same applies to the right rear, the left rear needs 3/4 >> turn. If all of the final adjustment were going to compensate for further >> bedding in, the further bedding would be ~.225 mm front and right rear >> and ~.38 mm left rear. >> If I can't attribute any or all of the "final adjustment" to bedding >> in, where would you attribute it to? > > Sorry to have taken so long to respond, but I've been trying to reason > this out, especially in the light of your experiences, which admittedly > are well beyond mine in terms of wheels built. > > I took some measurements on a Shimano hub (rear LX). I measured a flange > thickness at the hole of about 4mm. The holes are parallel to the axle. > The holes are countersunk about 1mm. The inside diameter seems about 2.8mm. > > This is my (current) best guess about what happens when you tighten & > overload a spoke: > > The spoke head is conical, so is self-centering in the countersink. In > that position, loaded with tension, it will resist rotation and > translation. With these assumptions, the part of the spoke between the > elbow and head can be considered to be a cantilevered beam of round > cross section, 2mm in diameter, ~3mm long, centered in a 2.8mm bore. > > When the spoke is first laced, it's likely that it is not centered. For > a left rear spoke, I'd guess that the first 1/3 tension centers the > head, the next 1/3 tension bends the shank down to contact the bore, and > the final 1/3 tension deforms the bore. Each of these represents about > 0.4mm of movement. This gives 0.4mm depth of deformation at the bore > edge. Front and right rear spokes go through the same movements, but the > additional 50kgf of tension deforms the bore edge another ~0.225mm. > > This explanation assumes that the first 35kgf of additional tension > after the spoke contacts the bore edge causes ~0.4mm of deformation, > while the next 50kgf only an additional ~0.225. I think these numbers > are reasonable because: > > The Rockwell hardness test for aluminum uses a 1.6mm ball with 100kg > load. A typical "penetration" is 0.14mm. The Rockwell test is designed > to operate in a reasonably linear region -- each "point" of hardness > corresponds to a certain depth increment. I think the geometry of the > spoke-on-bore loading is different enough to explain 0.14/100 to 0.4/35 > (~8:1 vs. Rockwell) and 0.225/50 (3:1) differences. > > The spoke-to-bore interface initially is cylinder to edge because the > cylinder makes a small angle (~5 deg) to the bore axis. This means that > the way the contact patch grows with deformation is very different than > the Rockwell ball on flat surface. I think this explains both the much > higher initial "penetrability" as well as the much greater > non-linearity. I haven't done the math to compute the volume/depth of > the contact patch, but I think the non-linearity is intuitively visible > since the contact patch both grows rapidly in area and grows back from > the unsupported edge. > > I'm assuming (for the context of your numbers) something like 70kgf > initial tension for left-rear, 100kgf front and right-rear, followed by > 105kgf left-rear and 150kgf front and right-rear peak during stress relief. in other words, additional tension /does/ cause additional spoke embedding. hooray. it only took 20 years to get there. |
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06-05.-2008, 10:08 PM
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#96 | |
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Registered User
Join Date: Sep 2003
Location: Suburban Chicago
Posts: 2,778
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Re: spoke fatigue troll
Quote:
Thank you Peter Cole for a well reasoned response. I use 150 kgf front and rear on both sides. That is why the additional 1/4 turn is required on left rear... I think. |
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07-05.-2008, 01:13 PM
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#97 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
"jim beam" wrote:
> Tom Sherman wrote: >> "jim beam" wrote: >>> Tom Sherman wrote: >>>> "jim beam" wrote: >>>>> Tom Sherman wrote: >>>>>> "jim beam" wrote: >>>>>>> Tom Sherman wrote: >>>>>>>> "jim beam" wrote: >>>>>>>>> Tom Sherman wrote: >>>>>>>>>> "jim beam" wrote: >>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>> [...] >>>>>>>>>>>>> nothing like the mental deformation we see from so-called >>>>>>>>>>>>> "engineers" >>>>>>>>>>>> >>>>>>>>>>>> Well, they are not "so-called" if granted a PE by a >>>>>>>>>>>> licensing board. >>>>>>>>>>>> >>>>>>>>>>>> What is your professional registration? >>>>>>>>>>>> >>>>>>>>>>>>> when they doggedly try to justify their underinformed >>>>>>>>>>>>> misconceptions. >>>>>>>>>>>> >>>>>>>>>>>> No hint of resentment here, eh? >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> refusing to address the "engineering" then tom? shouldn't be >>>>>>>>>>> too hard for a "professional" to do. unless they're a >>>>>>>>>>> lightweight of course. >>>>>>>>>> >>>>>>>>>> "jim" refuses to answer the question - does "he" have any >>>>>>>>>> professional registration? >>>>>>>>>> >>>>>>>>> >>>>>>>>> you want a sock puppet to answer? are you some kind of retard? >>>>>>>>> >>>>>>>>> discuss the engineering, s/n < 1:100 goddamned lightweight. >>>>>>>> >>>>>>>> "jim's" silence is deafening. >>>>>>>> >>>>>>> >>>>>>> goddamned hypocrite!!!!!!!! >>>>>>> >>>>>>> goddamned lightweight. >>>>>> >>>>>> Note "jim's" continued refusal to answer the question. >>>>>> >>>>> >>>>> are you some kind of retard? where will a "sock puppet" get any >>>>> kind of accreditation? muppet university? >>>>> >>>> Does the person with his hand up the sock puppet's posterior have >>>> any type of professional accreditation? >>> >>> the puppeteer needs no accreditation - all they need is the sock's >>> consent. >>> >> So "jim" is still ducking the question. > > ok, let me translate: "my privacy trumps your irritation". > I am not irritated at all. I enjoy pointing out the cowardice of hiding behind a sock puppet. >>>>> and get back to the engineering tom. here, let me replace what you >>>>> snipped: >>>>> >>>>> "brinell hardness # = P/pi.D.t >>>>> >>>>> where P = indenter load, D = indenter ball diameter and t = depth of >>>>> impression." >>>>> >>>>> so, as an "engineer", where's your argument about load and indenter >>>>> depth? >>>>> >>>> With the material previously work hardened or not? One does not run >>>> repetitive hardness tests on the same area, no? >>> >>> look up meyer's law. then convince me that you've understood it. >> >> In the case of a forged hub, the Meyer hardness would not change with >> indention depth, since the material started out being work hardened. >> For a cast hub flange, the Meyer hardness would continually increase >> as the test load was increased due to the cold working of the material. > > whoa - castings work harden but forgings don't??? Did I write that? No. I wrote that the Meyer hardness would not change, not that the material could not be further work hardened. The two are not the same. Learn to read. > wtf is it with you > engineers? don't you guys /ever/ pay attention in class??? that's a > classic right up there along with eliminating fatigue from a material > with no endurance limit! > Ibid. >>>>> goddamned lightweight. >>>> >>>> Ooooh, the wit of your insult is scathing. >>>> >>> >>> "insult" and "scathing"??? it's simple observation of fact! >>> >>> but i guess truth hurts. goddamned lightweight. >> >> Prove the existence of God then. >> > > you want a sock puppet to do that? come on tom, that's too lightweight, > even for you. You are the one who brought God into the discussion, "jim". -- Tom Sherman - Holstein-Friesland Bovinia The weather is here, wish you were beautiful |
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07-05.-2008, 01:18 PM
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#98 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
"jim beam" wrote:
> Tom Sherman wrote: >> "jim beam" wrote: >>> Tom Sherman wrote: >>>> "jim beam" wrote: >>>>> Tom Sherman wrote: >>>>>> "jim beam" wrote: >>>>>>> Tom Sherman wrote: >>>>>>>> "jim beam" wrote: >>>>>>>>> Tom Sherman wrote: >>>>>>>>>> "jim beam" wrote: >>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>> Ben C wrote: >>>>>>>>>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote: >>>>>>>>>>>>>>> jobst.brandt@stanfordalumni.org wrote: >>>>>>>>>>>>>>>> Stress relief. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> I think deformation of flange holes in aluminum hubs is >>>>>>>>>>>>>>>> being >>>>>>>>>>>>>>>> mis-characterized, leading to incorrect assumptions >>>>>>>>>>>>>>>> about effective >>>>>>>>>>>>>>>> spoke hole position before and after stress relieving >>>>>>>>>>>>>>>> and that >>>>>>>>>>>>>>>> trueness of the wheel suffers from the process. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Hole deformation is an asymptotic effect that with >>>>>>>>>>>>>>>> reasonable spoke >>>>>>>>>>>>>>>> tension is already as deep as it will get. If that were >>>>>>>>>>>>>>>> not so, >>>>>>>>>>>>>>>> spokes would gradually sink through the flange and pull >>>>>>>>>>>>>>>> out. Once >>>>>>>>>>>>>>>> about a third of the spoke diameter bears fully on the >>>>>>>>>>>>>>>> flange hole it >>>>>>>>>>>>>>>> is as deep as it will go while subsequent stress relief >>>>>>>>>>>>>>>> cannot "bed >>>>>>>>>>>>>>>> them in" any deeper as the process is often depicted >>>>>>>>>>>>>>>> here. The terms >>>>>>>>>>>>>>>> bedding in or stabilizing are a misnomers chosen by >>>>>>>>>>>>>>>> people who cannot >>>>>>>>>>>>>>>> visualize mechanical stress relief or that spokes bed in >>>>>>>>>>>>>>>> naturally >>>>>>>>>>>>>>>> from initial spoke tension. >>>>>>>>>>>>>>> The Rockwell hardness test (B scale, used for materials >>>>>>>>>>>>>>> like aluminum) uses a 1/16" (1.6mm) steel ball and >>>>>>>>>>>>>>> measures the depth indented with 100kgf. Typical hardness >>>>>>>>>>>>>>> numbers for aluminum would indicate a depth of around >>>>>>>>>>>>>>> 0.14mm (into a flat surface of reasonable thickness). >>>>>>>>>>>>>>> While the scenario is a bit different, the dimensions and >>>>>>>>>>>>>>> forces are similar. Given that the spoke and hole >>>>>>>>>>>>>>> diameters are close and the angle is small, it seems that >>>>>>>>>>>>>>> the absolute "bedding in" is small and happens early >>>>>>>>>>>>>>> (with tension). From there it seems safe to assume that >>>>>>>>>>>>>>> stress relief doesn't cause any significant additional >>>>>>>>>>>>>>> "bedding in". >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Perhaps this issue is finally put to bed. >>>>>>>>>>>>>> >>>>>>>>>>>>>> I'm not quite ready to put it to bed yet. >>>>>>>>>>>>>> >>>>>>>>>>>>>> The most likely explanation in my mind is that during >>>>>>>>>>>>>> stabilization the >>>>>>>>>>>>>> spoke cuts into a new part of the hub flange (the outside >>>>>>>>>>>>>> edge of the >>>>>>>>>>>>>> hole probably) that it wasn't quite bearing on before. The >>>>>>>>>>>>>> parts it's >>>>>>>>>>>>>> already been pulled against by tensioning don't deform any >>>>>>>>>>>>>> further for >>>>>>>>>>>>>> the reasons you state. >>>>>>>>>>>>> >>>>>>>>>>>>> this is /so/ basic. if you increase the force, you get a >>>>>>>>>>>>> bigger >>>>>>>>>>>>> indentation. all you have to do is look at the formula: >>>>>>>>>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...] >>>>>>>>>>>>> >>>>>>>>>>>> Does not the area deformed during initial tensioning work >>>>>>>>>>>> harden, and would that not reduce the deformation from spoke >>>>>>>>>>>> squeezing? >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> why do you think hardness numbers are comparatively, not >>>>>>>>>>> quantitatively correlated with strength? >>>>>>>>>>> >>>>>>>>>> For different materials obviously, but for the same material? >>>>>>>>>> >>>>>>>>> >>>>>>>>> oh dear, another "engineer" unclear on the concept. i'll ask >>>>>>>>> again, "why do you think hardness numbers are comparatively, >>>>>>>>> not quantitatively correlated with strength?". >>>>>>>>> >>>>>>>> That is irrelevant to the question at hand. In either case, work >>>>>>>> hardening of the hub flange at the spoke holes will reduce the >>>>>>>> amount of plastic deformation for a given future applied load, no? >>>>>>> >>>>>>> of course yes, but if you're unclear on the concept, and if you >>>>>>> can't read the math, then you're a goddamned lightweight if you >>>>>>> think it's not part of the hardness numbers!!! >>>>>>> >>>>>> Again, "jim" is introducing things tangential to the discussion at >>>>>> hand. >>>>> >>>>> eh? the math and theory behind hardness tester indentation is >>>>> "tangential" to spoke hole indentation??? what a goddamned >>>>> lightweight!!! >>>> >>>> Well, valid hardness tests are NOT performed on an area that has >>>> already been tested, and we were discussing additional deformation >>>> of an area of the spoke flange during spoke squeezing that was >>>> already deformed during tensioning. >>> >>> j.h.c. "valid" vs. "what" exactly tom??? or are you trying to be >>> dense? >>> >> Valid versus invalid. Duh. > > says the guy that doesn't understand work hardening! > Hint for "jim", if the hardness test (particularly Rockwell) is performed on an improperly prepared surface, the test will not be valid. >>> you've had a chance to do the math. you've had a chance to read the >>> cites. now, you tell me, if you have a rockwell hardness tester, >>> under "x" load it gives a reading, then, if you increase the load to >>> "x+1", same indentation, no withdrawal, are you telling me the >>> indenter will not sink further???? >>> >> Of course it will indent further, but not as far as if the test was >> performed on a non work-hardened area. > > dude, you are /hopelessly/ confused. /any/ indentation is subject to > work hardening. casting or forging. period. [and no hubs are cast > btw.] work hardening is not a step function. > So I can run multiple hardness tests on the same location on a piece of metal, and the results will not change between tests? >>>>>>>>> goddamned lightweight. >>>>>>>> >>>>>>>> You have keyboard macro's for insults? >>>>>>>> >>>>>>> >>>>>>> no, it's lovingly typed out by hand, just for you. and it's an >>>>>>> observation of fact. goddamned lightweight. >>>>>> >>>>>> "How to Win Friends and Influence People" - revised and updated by >>>>>> "jim beam". >>>>>> >>>>> >>>>> ask me if i give a flying one about the friendship and influence of >>>>> goddamned lightweights! >>>> >>>> Yep, only because you hide behind a sock puppet. You would not be so >>>> free with the insults if you had to use your real name, eh? >>>> >>> >>> if i were a lightweight like "tom sherman", i sure wouldn't use a >>> real name, that's for dead cretian! >>> >> What does "cretian" mean? >> > > it's a more clinical form of "lightweight". gene does a better job of mangling English, since his distortions are deliberate. -- Tom Sherman - Holstein-Friesland Bovinia The weather is here, wish you were beautiful |
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07-05.-2008, 01:31 PM
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#99 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
Tom Sherman wrote:
> "jim beam" wrote: >> Tom Sherman wrote: >>> "jim beam" wrote: >>>> Tom Sherman wrote: >>>>> "jim beam" wrote: >>>>>> Tom Sherman wrote: >>>>>>> "jim beam" wrote: >>>>>>>> Tom Sherman wrote: >>>>>>>>> "jim beam" wrote: >>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>>> [...] >>>>>>>>>>>>>> nothing like the mental deformation we see from so-called >>>>>>>>>>>>>> "engineers" >>>>>>>>>>>>> >>>>>>>>>>>>> Well, they are not "so-called" if granted a PE by a >>>>>>>>>>>>> licensing board. >>>>>>>>>>>>> >>>>>>>>>>>>> What is your professional registration? >>>>>>>>>>>>> >>>>>>>>>>>>>> when they doggedly try to justify their underinformed >>>>>>>>>>>>>> misconceptions. >>>>>>>>>>>>> >>>>>>>>>>>>> No hint of resentment here, eh? >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> refusing to address the "engineering" then tom? shouldn't >>>>>>>>>>>> be too hard for a "professional" to do. unless they're a >>>>>>>>>>>> lightweight of course. >>>>>>>>>>> >>>>>>>>>>> "jim" refuses to answer the question - does "he" have any >>>>>>>>>>> professional registration? >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> you want a sock puppet to answer? are you some kind of retard? >>>>>>>>>> >>>>>>>>>> discuss the engineering, s/n < 1:100 goddamned lightweight. >>>>>>>>> >>>>>>>>> "jim's" silence is deafening. >>>>>>>>> >>>>>>>> >>>>>>>> goddamned hypocrite!!!!!!!! >>>>>>>> >>>>>>>> goddamned lightweight. >>>>>>> >>>>>>> Note "jim's" continued refusal to answer the question. >>>>>>> >>>>>> >>>>>> are you some kind of retard? where will a "sock puppet" get any >>>>>> kind of accreditation? muppet university? >>>>>> >>>>> Does the person with his hand up the sock puppet's posterior have >>>>> any type of professional accreditation? >>>> >>>> the puppeteer needs no accreditation - all they need is the sock's >>>> consent. >>>> >>> So "jim" is still ducking the question. >> >> ok, let me translate: "my privacy trumps your irritation". >> > I am not irritated at all. I enjoy pointing out the cowardice of hiding > behind a sock puppet. cowardice??? like you'd say that to my face! i simply choose not to play your game. goddamned lightweight. > >>>>>> and get back to the engineering tom. here, let me replace what >>>>>> you snipped: >>>>>> >>>>>> "brinell hardness # = P/pi.D.t >>>>>> >>>>>> where P = indenter load, D = indenter ball diameter and t = depth of >>>>>> impression." >>>>>> >>>>>> so, as an "engineer", where's your argument about load and >>>>>> indenter depth? >>>>>> >>>>> With the material previously work hardened or not? One does not run >>>>> repetitive hardness tests on the same area, no? >>>> >>>> look up meyer's law. then convince me that you've understood it. >>> >>> In the case of a forged hub, the Meyer hardness would not change with >>> indention depth, since the material started out being work hardened. >>> For a cast hub flange, the Meyer hardness would continually increase >>> as the test load was increased due to the cold working of the material. >> >> whoa - castings work harden but forgings don't??? > > Did I write that? No. you wrote: "Meyer hardness would not change with indention depth, since the material started out being work hardened". you clearly don't understand what work hardening is. or meyer hardness for that matter. work hardening is a continuous function - it doesn't just reach a certain level, then stop. meyer hardness is for the projected area of the impression, not just the indenter impression. > I wrote that the Meyer hardness would not change, > not that the material could not be further work hardened. The two are > not the same. Learn to read. oh, the hypocrisy. you goddamned lightweight. > >> wtf is it with you >> engineers? don't you guys /ever/ pay attention in class??? that's a >> classic right up there along with eliminating fatigue from a material >> with no endurance limit! >> > Ibid. see above. > >>>>>> goddamned lightweight. >>>>> >>>>> Ooooh, the wit of your insult is scathing. >>>>> >>>> >>>> "insult" and "scathing"??? it's simple observation of fact! >>>> >>>> but i guess truth hurts. goddamned lightweight. >>> >>> Prove the existence of God then. >>> >> >> you want a sock puppet to do that? come on tom, that's too lightweight, >> even for you. > > You are the one who brought God into the discussion, "jim". > so you really /do/ want a sock puppet to theologize for you??? what a goddamned lightweight! |
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07-05.-2008, 01:36 PM
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#100 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
Tom Sherman wrote:
> "jim beam" wrote: >> Tom Sherman wrote: >>> "jim beam" wrote: >>>> Tom Sherman wrote: >>>>> "jim beam" wrote: >>>>>> Tom Sherman wrote: >>>>>>> "jim beam" wrote: >>>>>>>> Tom Sherman wrote: >>>>>>>>> "jim beam" wrote: >>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>>> Ben C wrote: >>>>>>>>>>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote: >>>>>>>>>>>>>>>> jobst.brandt@stanfordalumni.org wrote: >>>>>>>>>>>>>>>>> Stress relief. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> I think deformation of flange holes in aluminum hubs is >>>>>>>>>>>>>>>>> being >>>>>>>>>>>>>>>>> mis-characterized, leading to incorrect assumptions >>>>>>>>>>>>>>>>> about effective >>>>>>>>>>>>>>>>> spoke hole position before and after stress relieving >>>>>>>>>>>>>>>>> and that >>>>>>>>>>>>>>>>> trueness of the wheel suffers from the process. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Hole deformation is an asymptotic effect that with >>>>>>>>>>>>>>>>> reasonable spoke >>>>>>>>>>>>>>>>> tension is already as deep as it will get. If that >>>>>>>>>>>>>>>>> were not so, >>>>>>>>>>>>>>>>> spokes would gradually sink through the flange and pull >>>>>>>>>>>>>>>>> out. Once >>>>>>>>>>>>>>>>> about a third of the spoke diameter bears fully on the >>>>>>>>>>>>>>>>> flange hole it >>>>>>>>>>>>>>>>> is as deep as it will go while subsequent stress relief >>>>>>>>>>>>>>>>> cannot "bed >>>>>>>>>>>>>>>>> them in" any deeper as the process is often depicted >>>>>>>>>>>>>>>>> here. The terms >>>>>>>>>>>>>>>>> bedding in or stabilizing are a misnomers chosen by >>>>>>>>>>>>>>>>> people who cannot >>>>>>>>>>>>>>>>> visualize mechanical stress relief or that spokes bed >>>>>>>>>>>>>>>>> in naturally >>>>>>>>>>>>>>>>> from initial spoke tension. >>>>>>>>>>>>>>>> The Rockwell hardness test (B scale, used for materials >>>>>>>>>>>>>>>> like aluminum) uses a 1/16" (1.6mm) steel ball and >>>>>>>>>>>>>>>> measures the depth indented with 100kgf. Typical >>>>>>>>>>>>>>>> hardness numbers for aluminum would indicate a depth of >>>>>>>>>>>>>>>> around 0.14mm (into a flat surface of reasonable >>>>>>>>>>>>>>>> thickness). While the scenario is a bit different, the >>>>>>>>>>>>>>>> dimensions and forces are similar. Given that the spoke >>>>>>>>>>>>>>>> and hole diameters are close and the angle is small, it >>>>>>>>>>>>>>>> seems that the absolute "bedding in" is small and >>>>>>>>>>>>>>>> happens early (with tension). From there it seems safe >>>>>>>>>>>>>>>> to assume that stress relief doesn't cause any >>>>>>>>>>>>>>>> significant additional "bedding in". >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Perhaps this issue is finally put to bed. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I'm not quite ready to put it to bed yet. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> The most likely explanation in my mind is that during >>>>>>>>>>>>>>> stabilization the >>>>>>>>>>>>>>> spoke cuts into a new part of the hub flange (the outside >>>>>>>>>>>>>>> edge of the >>>>>>>>>>>>>>> hole probably) that it wasn't quite bearing on before. >>>>>>>>>>>>>>> The parts it's >>>>>>>>>>>>>>> already been pulled against by tensioning don't deform >>>>>>>>>>>>>>> any further for >>>>>>>>>>>>>>> the reasons you state. >>>>>>>>>>>>>> >>>>>>>>>>>>>> this is /so/ basic. if you increase the force, you get a >>>>>>>>>>>>>> bigger >>>>>>>>>>>>>> indentation. all you have to do is look at the formula: >>>>>>>>>>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...] >>>>>>>>>>>>>> >>>>>>>>>>>>> Does not the area deformed during initial tensioning work >>>>>>>>>>>>> harden, and would that not reduce the deformation from >>>>>>>>>>>>> spoke squeezing? >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> why do you think hardness numbers are comparatively, not >>>>>>>>>>>> quantitatively correlated with strength? >>>>>>>>>>>> >>>>>>>>>>> For different materials obviously, but for the same material? >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> oh dear, another "engineer" unclear on the concept. i'll ask >>>>>>>>>> again, "why do you think hardness numbers are comparatively, >>>>>>>>>> not quantitatively correlated with strength?". >>>>>>>>>> >>>>>>>>> That is irrelevant to the question at hand. In either case, >>>>>>>>> work hardening of the hub flange at the spoke holes will reduce >>>>>>>>> the amount of plastic deformation for a given future applied >>>>>>>>> load, no? >>>>>>>> >>>>>>>> of course yes, but if you're unclear on the concept, and if you >>>>>>>> can't read the math, then you're a goddamned lightweight if you >>>>>>>> think it's not part of the hardness numbers!!! >>>>>>>> >>>>>>> Again, "jim" is introducing things tangential to the discussion >>>>>>> at hand. >>>>>> >>>>>> eh? the math and theory behind hardness tester indentation is >>>>>> "tangential" to spoke hole indentation??? what a goddamned >>>>>> lightweight!!! >>>>> >>>>> Well, valid hardness tests are NOT performed on an area that has >>>>> already been tested, and we were discussing additional deformation >>>>> of an area of the spoke flange during spoke squeezing that was >>>>> already deformed during tensioning. >>>> >>>> j.h.c. "valid" vs. "what" exactly tom??? or are you trying to be >>>> dense? >>>> >>> Valid versus invalid. Duh. >> >> says the guy that doesn't understand work hardening! >> > Hint for "jim", if the hardness test (particularly Rockwell) is > performed on an improperly prepared surface, the test will not be valid. balderdash. you were bleating about work hardening, and getting it badly wrong. and here you are strawman bullshitting about surface preparation. tom, you're a goddamned lightweight. > >>>> you've had a chance to do the math. you've had a chance to read the >>>> cites. now, you tell me, if you have a rockwell hardness tester, >>>> under "x" load it gives a reading, then, if you increase the load to >>>> "x+1", same indentation, no withdrawal, are you telling me the >>>> indenter will not sink further???? >>>> >>> Of course it will indent further, but not as far as if the test was >>> performed on a non work-hardened area. >> >> dude, you are /hopelessly/ confused. /any/ indentation is subject to >> work hardening. casting or forging. period. [and no hubs are cast >> btw.] work hardening is not a step function. >> > So I can run multiple hardness tests on the same location on a piece of > metal, and the results will not change between tests? you're not running multiple tests, your proving that under increasing load, the indenter impression continues to deepen. goddamned lightweight. > >>>>>>>>>> goddamned lightweight. >>>>>>>>> >>>>>>>>> You have keyboard macro's for insults? >>>>>>>>> >>>>>>>> >>>>>>>> no, it's lovingly typed out by hand, just for you. and it's an >>>>>>>> observation of fact. goddamned lightweight. >>>>>>> >>>>>>> "How to Win Friends and Influence People" - revised and updated >>>>>>> by "jim beam". >>>>>>> >>>>>> >>>>>> ask me if i give a flying one about the friendship and influence >>>>>> of goddamned lightweights! >>>>> >>>>> Yep, only because you hide behind a sock puppet. You would not be >>>>> so free with the insults if you had to use your real name, eh? >>>>> >>>> >>>> if i were a lightweight like "tom sherman", i sure wouldn't use a >>>> real name, that's for dead cretian! >>>> >>> What does "cretian" mean? >>> >> >> it's a more clinical form of "lightweight". > > gene does a better job of mangling English, since his distortions are > deliberate. > so are mine - goddamned lightweight. |
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07-05.-2008, 01:39 PM
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#101 |
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Guest
Posts: n/a
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Re: spoke fatigue troll
jim beam wrote: > Tom Sherman wrote: >> "jim beam" wrote: >>> Tom Sherman wrote: >>>> "jim beam" wrote: >>>>> Tom Sherman wrote: >>>>>> "jim beam" wrote: >>>>>>> Tom Sherman wrote: >>>>>>>> "jim beam" wrote: >>>>>>>>> Tom Sherman wrote: >>>>>>>>>> "jim beam" wrote: >>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>> Tom Sherman wrote: >>>>>>>>>>>>>> "jim beam" wrote: >>>>>>>>>>>>>>> Ben C wrote: >>>>>>>>>>>>>>>> On 2008-05-02, Peter Cole <peter_cole@verizon.net> wrote: >>>>>>>>>>>>>>>>> jobst.brandt@stanfordalumni.org wrote: >>>>>>>>>>>>>>>>>> Stress relief. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I think deformation of flange holes in aluminum hubs >>>>>>>>>>>>>>>>>> is being >>>>>>>>>>>>>>>>>> mis-characterized, leading to incorrect assumptions >>>>>>>>>>>>>>>>>> about effective >>>>>>>>>>>>>>>>>> spoke hole position before and after stress relieving >>>>>>>>>>>>>>>>>> and that >>>>>>>>>>>>>>>>>> trueness of the wheel suffers from the process. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Hole deformation is an asymptotic effect that with >>>>>>>>>>>>>>>>>> reasonable spoke >>>>>>>>>>>>>>>>>> tension is already as deep as it will get. If that >>>>>>>>>>>>>>>>>> were not so, >>>>>>>>>>>>>>>>>> spokes would gradually sink through the flange and >>>>>>>>>>>>>>>>>> pull out. Once >>>>>>>>>>>>>>>>>> about a third of the spoke diameter bears fully on the >>>>>>>>>>>>>>>>>> flange hole it >>>>>>>>>>>>>>>>>> is as deep as it will go while subsequent stress >>>>>>>>>>>>>>>>>> relief cannot "bed >>>>>>>>>>>>>>>>>> them in" any deeper as the process is often depicted >>>>>>>>>>>>>>>>>> here. The terms >>>>>>>>>>>>>>>>>> bedding in or stabilizing are a misnomers chosen by >>>>>>>>>>>>>>>>>> people who cannot >>>>>>>>>>>>>>>>>> visualize mechanical stress relief or that spokes bed >>>>>>>>>>>>>>>>>> in naturally >>>>>>>>>>>>>>>>>> from initial spoke tension. >>>>>>>>>>>>>>>>> The Rockwell hardness test (B scale, used for materials >>>>>>>>>>>>>>>>> like aluminum) uses a 1/16" (1.6mm) steel ball and >>>>>>>>>>>>>>>>> measures the depth indented with 100kgf. Typical >>>>>>>>>>>>>>>>> hardness numbers for aluminum would indicate a depth of >>>>>>>>>>>>>>>>> around 0.14mm (into a flat surface of reasonable >>>>>>>>>>>>>>>>> thickness). While the scenario is a bit different, the >>>>>>>>>>>>>>>>> dimensions and forces are similar. Given that the spoke >>>>>>>>>>>>>>>>> and hole diameters are close and the angle is small, it >>>>>>>>>>>>>>>>> seems that the absolute "bedding in" is small and >>>>>>>>>>>>>>>>> happens early (with tension). From there it seems safe >>>>>>>>>>>>>>>>> to assume that stress relief doesn't cause any >>>>>>>>>>>>>>>>> significant additional "bedding in". >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Perhaps this issue is finally put to bed. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> I'm not quite ready to put it to bed yet. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> The most likely explanation in my mind is that during >>>>>>>>>>>>>>>> stabilization the >>>>>>>>>>>>>>>> spoke cuts into a new part of the hub flange (the >>>>>>>>>>>>>>>> outside edge of the >>>>>>>>>>>>>>>> hole probably) that it wasn't quite bearing on before. >>>>>>>>>>>>>>>> The parts it's >>>>>>>>>>>>>>>> already been pulled against by tensioning don't deform >>>>>>>>>>>>>>>> any further for >>>>>>>>>>>>>>>> the reasons you state. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> this is /so/ basic. if you increase the force, you get a >>>>>>>>>>>>>>> bigger >>>>>>>>>>>>>>> indentation. all you have to do is look at the formula: >>>>>>>>>>>>>>> http://www.key-to-steel.com/Articles/Art140.htm [...] >>>>>>>>>>>>>>> >>>>>>>>>>>>>> Does not the area deformed during initial tensioning work >>>>>>>>>>>>>> harden, and would that not reduce the deformation from >>>>>>>>>>>>>> spoke squeezing? >>>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> why do you think hardness numbers are comparatively, not >>>>>>>>>>>>> quantitatively correlated with strength? >>>>>>>>>>>>> >>>>>>>>>>>> For different materials obviously, but for the same material? >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> oh dear, another "engineer" unclear on the concept. i'll ask >>>>>>>>>>> again, "why do you think hardness numbers are comparatively, >>>>>>>>>>> not quantitatively correlated with strength?". >>>>>>>>>>> >>>>>>>>>> That is irrelevant to the question at hand. In either case, >>>>>>>>>> work hardening of the hub flange at the spoke holes will >>>>>>>>>> reduce the amount of plastic deformation for a given future >>>>>>>>>> applied load, no? >>>>>>>>> >>>>>>>>> of course yes, but if you're unclear on the concept, and if you >> |
