10-09-2016, 07:01 PM | #11 |
Join Date: Nov 2012
Location: Australia WA
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Re: Knowing Your Own Strength and Bending Steel Bars
What I would do is find out how much ST you would have under the basic ST system to have as much Basic Lift as you do with your KYOS score, and just use that number for any situation when KYOS doesn't mesh with other rules.
So for your example, the 40ST guy would be using a score of 316 when it comes to bending steel bars, throwing and so on. This should suffice until we finally get some more rules adaptions for KYOS. |
10-09-2016, 07:05 PM | #12 | |
Join Date: Nov 2008
Location: Yukon, OK
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Re: Knowing Your Own Strength and Bending Steel Bars
Quote:
But there has to be some retooling and I haven't thought about how. That is what I was talking about, they need to be posted elsewhere for those not into DF.
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My GURPS publications GURPS Powers: Totem and Nature Spirits; GURPS Template Toolkit 4: Spirits; Pyramid articles. Buying them lets us know you want more! My GURPS fan contribution and blog: REFPLace GURPS Landing Page My List of GURPS You Tube videos (plus a few other useful items) My GURPS Wiki entries |
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10-11-2016, 11:14 AM | #13 |
Join Date: Nov 2008
Location: Yukon, OK
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Re: Knowing Your Own Strength and Bending Steel Bars
Since Knowing Your Own Strength uses Log ST a thought occurred to me.
Turns out it wont work but rechecking the article there is a formula for converting old ST to Log ST (page 17 below the table) and that could be used to reverse it the other way. Its not pretty but should be accurate.
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My GURPS publications GURPS Powers: Totem and Nature Spirits; GURPS Template Toolkit 4: Spirits; Pyramid articles. Buying them lets us know you want more! My GURPS fan contribution and blog: REFPLace GURPS Landing Page My List of GURPS You Tube videos (plus a few other useful items) My GURPS Wiki entries |
10-11-2016, 03:01 PM | #14 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: Knowing Your Own Strength and Bending Steel Bars
Now for some Science!. Bear in mind that these results will at most accidentally resemble any existing GURPS rules.
Standard A36 steel has a yield strength of 36,000 psi and an ultimate tensile strength of 58-80,000 psi; a 1" steel bar has a cross-section of pi/4 square inches, so it takes 28,000 lbf to force it to yield and 45-62,000 lbf to snap it. To do that as 1x BL (in KYOS) requires a ST of log10(required force in lb)x10 - 3, or ST 42 to yield, ST 44-45 to break. To do it as BLx3 (max 1H) subtract 5 from required ST; to do it as BLx8 (max 2h) subtract 9. The force required varies with the square of thickness, so add 20 x log10(thickness in inches) to required ST. However, you're not actually trying to pull the steel bar apart like taffy -- you're trying to bend it. This is much easier, because we have leverage. It only requires around 400 ft-lb of torque to very slightly bend a 1" steel bar; because of the complexity of the steel stress-strain curve, you need much more force to generate large changes, so increase that to around triple for large changes such as tying it in knots. For other thicknesses, this varies with the cube of the bar diameter. For a rod that's firmly attached to some material, the amount of force you can apply to it is equal to the distance between your hands and the attachment point, times the force you can apply. Thus, if you have a firmly steel bar that's 1" in diameter and 3' long, you can slightly bend it with 133 lb force, and probably bend it flat with 400 lb; using two hands, that only requires ST 12-17. Add 30x log10(thickness in inches) - 10 x log10(length in yards) for other configurations. For a rod that is firmly attached at both ends and you're applying force in the middle, multiply the required force by 4, so ST 18-23. This also applies if you've got a free bar that you're bending with a three point grip. If you're trying to bend with a two point grip, you're limited by your hand torque, which is somewhere in the range of BLx1.5 ft-lb; unlike the other examples this isn't affected by the length of the rod unless it's shorter than your hand, and you require ST 22-27. To do it casually you should be doing it with a two point grip and have considerable excess ST, so somewhere in the 30s is about right. Other materials will use the same formulas with different constant terms. Last edited by Anthony; 10-11-2016 at 03:08 PM. |
Tags |
lifting strength, strength, super strength |
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