Column Critical Buckling Loads

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Subject Author Date Column Critical Buckling Loads Curbie 07-02-2009  Re: Column Critical Buckling Loads vaughn 07-02-2009  Re: Column Critical Buckling Loads Curbie 07-02-2009  Re: Column Critical Buckling Loads Neon John 07-02-2009  Re: Column Critical Buckling Loads Curbie 07-02-2009  Re: Column Critical Buckling Loads z 07-02-2009  Re: Column Critical Buckling Loads vaughn 07-02-2009  Re: Column Critical Buckling Loads z 07-02-2009  Re: Column Critical Buckling Loads Curbie 07-03-2009  Re: Column Critical Buckling Loads Neon John 07-03-2009  Re: Column Critical Buckling Loads z 07-03-2009  Re: Column Critical Buckling Loads Curbie 07-03-2009  Re: Column Critical Buckling Loads N9WOS 07-03-2009  Re: Column Critical Buckling Loads N9WOS 07-03-2009  Re: Column Critical Buckling Loads Curbie 07-03-2009  Re: Column Critical Buckling Loads daestrom 07-03-2009  Re: Column Critical Buckling Loads Curbie 07-03-2009
Posted by Curbie on July 2, 2009, 5:35 pm Please log in for more thread options I went back after the math behind calculating loads exerted on wind turbine tower masts and I'm still having trouble converting the formulas to a spread-sheet so the results match the examples given. The formula I'm having trouble converting is: (34,000/1.9)[1 - (1/2)(101.8/132)^2] = 10,994 My question is how do I convert the contents of the left square bracket "[" and right square bracket "]" to spread-sheet expression? Or maybe just what is the purpose of the brackets. Thanks for any help. Curbie Posted by vaughn on July 2, 2009, 6:08 pm Please log in for more thread options > > I went back after the math behind calculating loads exerted on wind > turbine tower masts and I'm still having trouble converting the > formulas to a spread-sheet so the results match the examples given. > > The formula I'm having trouble converting is: > (34,000/1.9)[1 - (1/2)(101.8/132)^2] = 10,994 > > My question is how do I convert the contents of the left square > bracket "[" and right square bracket "]" to spread-sheet expression? > Or maybe just what is the purpose of the brackets. > > Thanks for any help. Just change those square brackets to round ones. They were probably only made square to help us humans keep track of things. Computers (even cheap scientific calculators) can handle multiple nested round brackets just fine. Vaughn Posted by Curbie on July 2, 2009, 7:34 pm Please log in for more thread options Vaughn, >Just change those square brackets to round ones. That worked for me in the past but using this spread-sheet expression: (34000 / 1.9) * (1 - (1 / 2) * (101.8 / 132)^2) = 12,573 where their example is: (34,000/1.9)[1 - (1/2)(101.8/132)^2] = 10,994 Different results, and since these formulas where taken from some college physics department, I have to be interpreting that formula incorrectly. http://physics.uwstout.edu/StatStr/Statics/Columns/colse62c.htm I always look for examples with results so I can check my math for just this sort of mis-interpretation. Curbie Posted by Neon John on July 2, 2009, 8:39 pm Please log in for more thread options I worked this out by hand on a calculator to make sure I got my operator precedence correct and got your answer of 12,573. I can't get 10,994 using any combination of the numbers, even abusing precedence rules. I ran the formula using square root instead of square, figuring that the guy might have hit the wrong key on his calculator. That produces 10,037. Closer but no cigar. I think that he made a math error. Why not drop him a note and ask? John wrote: >Vaughn, > >>Just change those square brackets to round ones. >That worked for me in the past but using this spread-sheet expression: >(34000 / 1.9) * (1 - (1 / 2) * (101.8 / 132)^2) = 12,573 > >where their example is: >(34,000/1.9)[1 - (1/2)(101.8/132)^2] = 10,994 > >Different results, and since these formulas where taken from some >college physics department, I have to be interpreting that formula >incorrectly. > >http://physics.uwstout.edu/StatStr/Statics/Columns/colse62c.htm > >I always look for examples with results so I can check my math for >just this sort of mis-interpretation. > >Curbie Posted by Curbie on July 2, 2009, 9:16 pm Please log in for more thread options I'm sorry John, I didn't mean for anyone to run the calculations, just explain the use of the "[ ]". Do you think those "[ ]" could be replaced with "( )", it seems there has to be more than that and that one of the students would have run the math and gleefully pointed out the error (seems that would to be worth some extra credit)? > Why not drop him a note and ask? I'll try, I've never had any luck doing that, their pretty busy. Thanks, Curbie Similar Threads Posted Using a Kill-a-Watt with small 240 and 277 V loads August 31, 2007, 1:18 pm Calculating wind turbine tower loads February 23, 2009, 1:02 pm Re: Calculating wind turbine tower loads February 25, 2009, 12:54 pm Re: Calculating wind turbine tower loads February 25, 2009, 3:45 pm Re: Calculating wind turbine tower loads February 25, 2009, 3:52 pm Re: Calculating wind turbine tower loads March 2, 2009, 5:37 pm Re: Calculating wind turbine tower loads March 3, 2009, 4:43 am Re: Calculating wind turbine tower loads March 3, 2009, 10:30 am