Question

Q2. (15%)Flex ural Stress The distance between the supports is 15 ft and the overhang is eyo can use either method) e moment determine the maximum flexural stress irn a) Determine b) At the section with maximum positive the maximum moment in the beam (you can the cross-section. e) At the section with maximum det the cross-section. negat tive moment determine the maximum flexural stress in 1000 lb 500 lb/ft s d) Standard steel beam cross-section: W8 x 15 (height of beam i

Answer 1

e beam car Shouon as beloue re tooolb 500lb/L k- м, 8 5 PL H62.58 b t nd BMD oo lb-f Let RA, Rg be the reactions! at sup Total load RAt Re (500x 15)+ ooo 8500 lb RAtRO TakrY Moments about. Support A 2- R85083-33 1b RA8S00 5083.32

g.M at Sign. conu« B.M at A 2- Here mai -5000 lb-ft imum Negative 8M is ilar positive em obtain mocimum Shear Jorce becomes Zero ket, oc distance to "Zero 8-F 孑rom writing g.f .F eauation 500え= 4083-33 8.66 rom e lb-pt 11673.58 Given Cross Section of beam i W5 1 height of beam d- g. n Moment-eînerkia 48 사 r the relation o bendting equation

b) Max fletural stress at section 45% max positive Section h maoS momen M = 11643.58 lb ft 8. 1163-S8& 2. 34Xlo Censile) i, man-Ve momen c) Max flexural stress at Section a ,'. Max 위eaura.l atre &S ơm.ax-_y4 2-3lX 6 ft ompressiue.) ve moment500 lb fleauural stress at Section uth exural stress at Section m max positive b) Max moment PL )Max leural stress at section uslth mave Section uw mai ve momer fL-