Question

1) Using ultimate stress values from textbook table 21.3, a factor of safety of 1.5 and modulus of elasticity value of 3.6X10^6 psi Rectangular concrete (unreinforced) beam, 12 inch height, 4 inch wide 4,000 pound load Span 10 feet max allowable deflection, L/200 Is the deflection limit exceeded? Is maximum allowable stress exceeded? What is the maximum load the beam can withstand? Is deflection limit exceeded for this maximum load? What is the maximum load that meets both criteria? 2) Assume a bridge is made with two parallel beams (so that total load is equally divided among the beams). Ignore bridge deck weight. Using ultimate stress values from textbook table 21.3, a factor of safety of 1.5 and modulus of elasticity values from table 20.2 Rectangular steel beam, 6 inch height, 3 inch wide 13,000 pound total load Span 24 feet max allowable deflection, L/200 Is steel strong enough? Is deflection limit exceeded? What is the maximum load that meets both criteria?

Answer 1

0 0 3 Elenle Oltal than 6 max 200 4. Ebh? D: (6000 lb) . ! lokke) in *** 12 h A = 0.069 in 1 10x12 200 Amore e dope os 2016 in : deflection deniet does not exceeded as a < Armen si 3x [Yooo 6b) (10x120 in). 1250 psi ex ( 4 un ) x (12 in ) Palmek = wilkite stiune est = 293.33 Pi. :: Yes, mar" allowable shies exceeded as r 7 ballonnelle Gelende e r e format for rent het s Tebuie sa ne in cui • 13 2.0 06.] Dr Fre L² 3200 x (124/0² X 2 X 4X12 Smx 13 1.5x120 4661 4x (3.6x100), 4 x 12 13 ² 0.05 in < Amar o bun Hence, deflection limit does not exceeded for mar" allowable load ,

kb= 3in The bin Save ind, so parallel to lelques te beky 266 2662 S For = 3200 lb is the marth had which satisfies 1. kath Criteria of mar" deflection as well as Allamable strus. o fenomen so lo Pafflied on each bean Florid Sas 2 beam 1 STEEL a f = 13000 - 6500 lb. Frequal load - 1= 24 feet. 0=3F.L. 341610wle] [24x12 mi) – 260046 / - 2x [ 3 in 3x [bine The pure: 36oo khach Posted on the image photos 2400 Website ... r> Pallerier Hence steel is not strong enough. As fls . 1690653 ( 21x12 en ) 2.065 m. 13 = 2.9 ** Psi(baw Amar - I . wir in a 1.49 in - 2 Youo 1.5 As entre to be 9810* W45) (sm)tex! Wur12i mara 20

"D) A max, Yes reflection limit exceeded. Bahanube + 2you keby to 3 , alsouvek ) 2x {su)? [6w)" Ahmet are you in a fit mens nie). a) for 600 lb. 49/2.93704 mil De 1 3wJx. 163) Fr. 4531.45 lb. is the maxim land Mence Mont of fiofie f = 4531.25 which will satisfy heath Criteria.