Question

Please write neatly. I often have trouble reading others handwriting. Thanks

2. Two 2x6 pieces of No 1 Southern Pine lumber were connected together to make a T-section to be used as a beam with a 12-ft span. What is the largest uniformly distributed load (dead and construction) that this beam can support? Consider shear, moment, and a maximum total deflection of L/240. Assume Cy® C,-Ci= Cr = 1 .0. 왈

Answer 1

Centroid: x^bar = sigma A_i x_i/sigma A_i = 5 1/2 times 1 1/2 times 1/2 times 5 1/2 times 5 1/2 times 1 1/2 times (5 1/2 + 1/2 + 1 1/2)/1 1/2 times 5 1/2 times 2 = 71.25/16.5 = 9.5^'' in finding I_xx I_xx = 1/12 times 1 1/2 times 5 (1/2)^3 + 5.5 times 1.5 times (5 - 5/2 - 4.5)^2 + 1/3 times 5 times 1.5^3 + 5.5 times 1.5 times 1^2 = 124.78 + 25.27 + 6.187 + 8.25 = 169.5 in^4 Section modular: Z_Top = I_xx/Y_Top = 164.5/2.5 ln^3 = 65.8 in^2 Z_bottom = I_xx /Y_bottom