- #1
propman07
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Hello-
This isn't a homework problem, but a real life problem. I'm trying to size a beam for a set of stairs that I'm trying to design. I have some material picked out, and it looks strong enough, but when I try to run some numbers to confirm, they don't appear to match what I've experienced in the real world.
Calculate the maximum deflection of a simply supported beam given the following:
Total length: 27 feet
Material: Steel (E=30x10^6 lb/in^2
Cross section: See image
Weight: 0.283 lb/in^3
Maximum deflection of uniformly loaded simply supported beam (from Schaum's Outline Series, Strength of Materials 2/ed, P.161)
y=5/384 * wL^4/EI
Using the given above, along with the following:
w = 104.107 lb/ft
I = 23.05 in^4
Using the maximum deflection equation from above solving for y yields:
y=259.23 inches
This means that the middle of the beam will deflect almost 260 inches due to it's own weight?? I must be doing something wrong...any help would be appreciated.
Thanks.
http://www.dom2.com/stairs/images/beam-x-section.jpg
This isn't a homework problem, but a real life problem. I'm trying to size a beam for a set of stairs that I'm trying to design. I have some material picked out, and it looks strong enough, but when I try to run some numbers to confirm, they don't appear to match what I've experienced in the real world.
Homework Statement
Calculate the maximum deflection of a simply supported beam given the following:
Total length: 27 feet
Material: Steel (E=30x10^6 lb/in^2
Cross section: See image
Weight: 0.283 lb/in^3
Homework Equations
Maximum deflection of uniformly loaded simply supported beam (from Schaum's Outline Series, Strength of Materials 2/ed, P.161)
y=5/384 * wL^4/EI
The Attempt at a Solution
Using the given above, along with the following:
w = 104.107 lb/ft
I = 23.05 in^4
Using the maximum deflection equation from above solving for y yields:
y=259.23 inches
This means that the middle of the beam will deflect almost 260 inches due to it's own weight?? I must be doing something wrong...any help would be appreciated.
Thanks.
http://www.dom2.com/stairs/images/beam-x-section.jpg
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