TRUSSES SAMPLE QUESTIONS

4 m r=400 mm 16 kN A C D B E F G H 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.

Cut FBC FCJ FFJ FG

3. Determine the forces in members CD, CJ and DJ, state whether they work in tension (T) or compression (C).

Ay T I. Cut 3 m FCD FDJ FJI Ax

Ax Ay T II. Cut FCD FCJ FKJ

4. The truss shown consists of 45° triangles 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 Vy Uy

III. Cut II. Cut I. Cut IV. Cut Vy=20 kN Uy=15 kN

6. Determine the forces in members DE, EI, FI and HI. 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.

II. Cut I. Cut III. Cut

2 m 4 m 3 m A B C D E F G N M L K J H P 10 kN 6 kN Radii of pulleys H, F and K 400 mm 4 kN 20 kN 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.

By Bx Ax (I) (II) (IV) (III) 4 kN 6 kN 10 kN F 10 kN 10 kN E H G 2 m B C D 10 kN Bx J 10 kN 2 m 20 kN N L K 10 kN 2 m Ax A P M 3 m 3 m 4 m 4 m 4 m 4 m Radii of pulleys H, F and K 400 mm

9. Determine the forces in members EF, NK and LK. G H O L K J I N 1 kN 2 kN 5 kN 4 m 3 m M 3 4 9. Determine the forces in members EF, NK and LK.

Ax, Ay and Iy FBN FMN FMO FHO FBA FHI Ax Ay Iy C B A D E F G H O L K J I N 1 kN 2 kN 3 kN 4 kN 4 m 3 m I. Cut Top Part Ay Iy M Ax FHI FHO FMO FMN FBN FBA From the equilibrium of whole truss Ax, Ay and Iy are determined I. Cut SMH=0 FAB is determined

FEF FMF FMO FMN FBN FBA II. Cut II. Cut Top Part SMM=0 D E F G H O L K J I N 1 kN 2 kN 3 kN 4 kN 4 m 3 m II. Cut Top Part M FEF FMF FMO FMN FBN FBA II. Cut SMM=0 FEF and FMF are determined

FEF FMF FMO FNK FLK III. Cut SMN=0 FLK and FNK are determined III. Cut B A D E F G H O L K J I N 1 kN 2 kN 3 kN 4 kN 4 m 3 m III. Cut Left Side M FMO FLK FNK FMF FEF III. Cut SMN=0 FLK and FNK are determined

10. Determine the forces in members KN, FC and CB. G P F N M I J K L H 10. Determine the forces in members KN, FC and CB.

III. Cut I. Cut II. Cut IV. Cut Ax By Ay Forces in KN, FC and CB. kN 1 m 2 m A B C D O E G P F N M I J K L H I. Cut II. Cut III. Cut IV. Cut By Ay Ax Forces in KN, FC and CB.