ARC322 Homework 17 SOLUTION

ARC322 Homework 17 SOLUTION - ARC322 Homework 17 16 Points...

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ARC322 Homework 17 16 Points KEY RYAN … on this one, they can use EITHER timber or beam allowable stresses … I’ve done it for both … EITHER solution is OK … 1. Select a wood beam for a span of 24 ft with a spacing of 6 ft OC where the DL+LL is 135lb/ft 2 using DFL NO.1. 4 points This Example is Case 2 M = w L 2 /8 … but, we don’t know “w” yet … DL+LL = 135lb/ft 2 x 6 ft = 810 lb/ft M = 810lb/ft(24ft) 2 /8 = 58,320 ft-lb If they Used a BEAM value … S = M/f = (58,320 ft-lb x 12in/ft)/1350 lb/in 2 518.4 in 3 12 x 18 S = 586.979 in 3 Area = 201.25 in 2 10 x 20 S = 602.063 in 3 Area = 185.25 in 2 8 x 22 S = 577.8 in 3 Area = 161.3 in 2 1 point 577.8 in 3 > 518 in 3 … OK 1 point If they Used a TIMBER value … NOTE … EITHER solution is OK S =M/f = (58,320 ft-lb x 12 in/ft)/1200 lb/in 2 = 583.2 in 3 12x18 S = 586.979 in 3 Area = 201.25 in 2 10 x 20 S = 602.063 in 3 Area = 185.25 in 2 8 x 24 S = 690.3 in 3 Area = 176.3 in
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This note was uploaded on 03/30/2008 for the course ARC 322 taught by Professor Mcgavin during the Winter '08 term at Cal Poly Pomona.

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ARC322 Homework 17 SOLUTION - ARC322 Homework 17 16 Points...

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