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This discussion explores the choice between yield and ultimate limit states in bolted tension connections. Analyzing the impact of stress limits on different brace lengths and the consequence on structural stability, it offers insights on how to prevent yielding to ensure structural integrity. The text delves into the complex effects of limiting stress and dealing with second-order effects in the context of structural design. In addition, it underlines the significance of the yield limit for components, contrasting it with the flexibility permissible around connection holes. 8 Relevant
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Limit State: Yield or Ultimate?? Yield: 36 ksi (strain = 0.0013)
Limit State: Yield or Ultimate?? 12’ 24’
Limit State: Yield or Ultimate?? P 12’ 322” long brace 24’
mmmm….. Maybe we should not let it yield P 12’ 322” long brace 24’
mmmm….. Maybe we should not let it yield P 12’ 322” long brace 24’
If we limit the stress to less than yield, then…. P 12’ 322” long brace 24’
If we limit the stress to less than yield, then…. P 12’ 322.4” long brace The brace would not extend more than 0.4” (do the math: eL = 0.4”) 24’
If we limit the stress to less than yield, then…. P 12’ 322.4” long brace The brace would not extend more than 0.4” (do the math: eL = 0.4”) And the column would be leaning by no more Than 0.45” (do the math: Pythagoran 24’
Then again…. Yield is no where near the maximum the steel can take. P 12’ 322” long brace 24’
Then again…. Yield is nowhere near the maximum stress the steel can take. P 12’ 322” long brace 24’
I mean…. Even if it yields at 36 ksi, it doesn’t break, right? P 12’ 322” long brace 24’
I mean…. Even if it yields at 36 ksi, it doesn’t break, right? P 12’ 322” long brace 24’
It seems like yielding is no big deal P 12’ 322” long brace 24’
It doesn’t break at 36 ksi (yield)Why not just say that 58 ksi (ultimate) is the limit?? P 12’ 322” long brace 24’
It doesn’t break at 36 ksi (yield)Why not just say that 58 ksi (ultimate) is the limit?? P 12’ 322” long brace 24’
If we limit the stress on the brace to Anything Less than Ultimate (58 ksi), then… P 12’ 322” long brace 24’
If we limit the stress on the brace to Anything Less than Ultimate (58 ksi), then… P 12’ 425” long brace 132” The brace would not extend more than 103” (do the math: eL = 103”) 24’
If we limit the stress on the brace to Anything Less than Ultimate (58 ksi), then… P 12’ 425” long brace 132” The brace would not extend more than 103” (do the math: eL = 103”) And the column would be leaning by about 132” (do the math: its fun, complicated) 24’
Now, we’re in the world of 2nd order effects (the Statics are changed because of the huge change in geometry P 12’ 425” long brace 132” The brace would not extend more than 103” (do the math: eL = 103”) And the column would be leaning by about 132” (do the math: its fun, complicated) 24’
Gravity loads will make it collapse P 12’ 425” long brace 132” The brace would not extend more than 103” (do the math: eL = 103”) And the column would be leaning by about 132” (do the math: its fun, complicated) 24’
Around holes, a little bit of yielding is fine (holes are tiny).
