Question

STANDARD VIEW PRINTER VERSION Chapter 4, Problem 4/009 Determine the force in each member of the loaded truss. Make use of symmetry of the truss and of the loading. Forces are positive if in tension, negative if in compression 3.3 m 4.1 m 4.1 m 4.1 m 4.1 m HGF 36 kN si kN 36 KN Answers:

Answer 1

I /uim uilm u im Ulm 0 36KN 51KN 36kN Ay Finding Teachons : {fy = 0 25 [Ax=0] Efyzo Ay-36-51-36 + Ey so Ay thy = 36+51 +36 Ay tEy = 123kN EMA=0 Ey (16.4) = (36X0:19 +51 9.2.) +(6 x 12.3) Fy = 61.5 KN Ay = 123-61.5 Ay = 61.5 IN JAS AB 5.26 Joint Ai 0 --> AH- 0 --SAN 1 61.5 KN 61.5KN Efx=0 AH+ (u. 1 JAB=0 3. 3 Ery = 0 5 Sned with G1 - CamScanner 0 AB = 6 AB = 61.5 -98-086 kN 0.627.

A B = AB= -98-086 KN 98.086 KN (compression) AH = -(411(-99.086) AH = 76.456 KN (Tension) Joint B Вс tano= 3.3 mol 138.33 AB BH AB Sin 38.83 BC AB Cos* 38.83 BH- Sin 38.83) Ery=0 BH = 98.086 X BH = 61.5 IN F250 BC + AB Cos 38.83 20 BC = -(98.636 x cos 18-837 BC = 76.41KN BC = 76.41 KN (compression) À DE sino Joint ® DE ↑ Ey Scanned with CamScanner

Efx=0 EF + DECO =O EF = -(92.034 XCOS 830.83) EF = 36 76.41 KN (Tension) If y=0 Ey + DESin (38.83) = 0 DE = -61.5 Sin (38.83) DE = -98.024 EN DE = 98. 08u KN ( Compression) Joint : DE Sin 37.23 CD 98.83 OR DE CD DECOS 32-23 DF Ery=0 DF a = DE Sin 38.83 DF = (98.084 Sin 37.83) DF = 61.5kN (Tension] SEX=0 CD + DE cos 38.83 = 6 CD= -1 98.084 x cos 30.83] CD -76.41KN CD=76.41 KN (compression) Scanned with CamScanner

Joint Fi cf sino CFR 1 DF OCb -_ GF - CF COSO EF 36 Efy=0 CF Sino & DF =36 CF = 36- 61.5 Sin (38.83.) CF = -40.67 KN CF = 40.67 kN (compression) Ifx=0 CF Coso + GF = EF GF = 76.61 - [ 4o. 67 x cos (38.83)] GF = uy. 73kN (Tension) Joint Go GH < o GF I FX 20 GH =GR GH - uu.73KN (Tension 1 CG = SIIN (Tension) Scanned with CamScanner

Joint ci os BC CH CG CD BC S CD cf CF Sino со CF cos@ CHCOSO BC FCG ICH sino I Styco CH sino +CG = CF Sino CG= 40.67x sin 38.83) --40.67 sin 38.83 CG= 51kW {Fr=o. BC fcHcoso Relac CD + CFcoso CH = + BC - CD -Cfcose cosce (76.41 - 76.41 - Cos (38.83) (40.67 x cos 38.83) CH 2 -31.68 0.779 Canned witCH = -40.67 IN Scanner CH-40.67 INC compte

Joint G; - o GF HG اک Efn=o HG = GF HG = 44.73 kcal (Tension] Joint H: 1 Bitch ho AG 26 АН, 36IN BH w AG CHCOSO 36 V CHsino. Fy=0 BH = 36+ Chisina BH = 36 + [40.67 x Sin (398337 (Tension 2 BH = 61. 5kN canned with am Scanner