Question

What is the deflection of a W12x30 16 ft long with a distributed load of 2k/ft? Include the weight of the beam. a) 0.027in b) 0.055in c) 0.434in d) 0.832in

Answer 1

correct answer is option C)

Step-by-step explanation:

W 12 x 30 section of the beam dimension

Value of E = 29000 ks i/in²

I = 238 in⁴

weight of beams per length = 30 lbs/ft = 30 × 10⁻³ ks i/ft = 2.5 × 10⁻³ ks i/in.

distribution load = 2 k/ft = 1/6 k/in

L = 16 × 12 = 192 inch.

deflection due to distributed load =
`(5)/(384)(wl^4)/(EI)`

=
`(5)/(384)* (192^4)/(6* 29000* 238)`

= 0.427 in.

deflection due to self weight =
`(wl^4)/(48EI)`

=
`(2.5 * 10^(-3)* 192^4)/(48* 29000* 238)`

= 0.01025 inch

total deflection = 0.427 in.+ 0.01025 inch

total deflection = 0.4375 in

correct answer is option C)