Transcript Slide 1
TRUSSES SAMPLE QUESTIONS 4m 4m 4m E D 4m r=400 mm H G C F 4m B 16 kN 4m A 1. The crane in the figure consists of a planar truss. Determine the forces in members DE, DG and HG when the crane supports a 16 kN load, indicate whether the members work in tension (T) or compression (C). 2. Determine the forces in members BC and FG. FCJ Cut FBC FFJ FG 3. Determine the forces in members CD, CJ and DJ, state whether they work in tension (T) or compression (C). I. Cut 3m T FJI FDJ FCD Ax Ay T FKJ FCJ FCD Ax Ay II. Cut 4. The truss shown consists of 45° triangles. The cross members in the two center panels that do not touch each other are slender bars which are incapable of carrying compressive loads. Identify the two tension members in these panels and determine the forces they support. Also determine the force in member MN. I. Cut Ax II. Cut Ay By 5. Determine the force acting in member DK. Ux Uy Vy II. Cut III. Cut I. Cut IV. Cut Uy=15 kN Vy=20 kN 4/47 6. Determine the forces in members DE, EI, FI and HI. II. Cut I. Cut Gx Ay Gy 7. Determine the forces in members ME, NE and QG. I. Cut II. Cut III. Cut 4 kN 10 kN 6 kN F E H G 2m B C D J 2m N K L 2m A 3m 20 kN M P 3m 4m 4m 4m 4m Radii of pulleys H, F and K 400 mm 8. In the truss system shown determine the forces in members EK, LF, FK and CN, state whether they work in tension (T) or compression (C). Crossed members do not touch each other and are slender bars that can only support tensile loads. (I) (II) (IV) By 4 kN 10 kN 6 kN F E 10 kN 10 kN (III) 2m B C G D 10 kN Bx 10 kN 2m J 20 kN N K L 2m Ax H A 3m 10 kN M P 3m 4m 4m 4m 4m Radii of pulleys H, F and K 400 mm C 2 kN 2 kN 2 kN D E F 5 kN 3 G 4 1 kN 4m O N H B M 4m A I L 2 kN 3m J K 2 kN 2 kN 3m 3m 3m 9. Determine the forces in members EF, NK and LK. C 2 kN 2 kN 2 kN 3 kN D E F G 4 kN From the equilibrium of whole truss 1 kN 4m I. Cut N Top Part O M B FMN FBN FHO FMO FHI A I L Ay 2 kN 3m J K 2 kN 2 kN 3m 3m are determined H FBA Ax Ax, Ay and Iy 3m Iy 4m I. Cut SMH=0 FAB is determined C 2 kN 2 kN D E 3 kN 2 kN FEF G F 4 kN 1 kN FMF II. Cut Top Part 4m II. Cut N O M B FMN FBN SMM=0 H FMO FBA 4m A I L 2 kN 3m J K 2 kN 2 kN 3m 3m 3m FEF and FMF are determined C 2 kN 2 kN D E 3 kN 2 kN FEF G F 4 kN 1 kN FMF N FMO M B 4m O H III. Cut SMN=0 4m FNK A I L 2 kN 3m K J 2 kN 2 kN FLK 3m III. Cut Left Side 3m 3m FLK and FNK are determined 25 2 kN G 1m H I F P E 10 2 kN 10 2 kN 1m N M O 1m L J K D C 25 2 kN 20 2 2m B A 2m kN 1m 1m 2m 10. Determine the forces in members KN, FC and CB. 25 2 kN G III. Cut I. Cut H I F P 1m E 10 2 kN 10 2 kN 1m N M J K O 1m D C L II. Cut 25 2 kN 20 2 IV. Cut Ax kN 2m B A 2m 1m Ay 2m 1m By Forces in KN, FC and CB.