simple truss analysis method of sections
TRANSCRIPT
Simple Truss AnalysisMethod of Sections
Engineering Mechanics: Statics * Dr. Yiheng Wang
Objective of this video:
To provide a step-by-step problem-solving strategy for simple truss analysis using the method of sections.
Engineering Mechanics: Statics * Dr. Yiheng Wang
F F
F F
tension
compression
F F
F F
F F
F F
Engineering Mechanics: Statics * Dr. Yiheng Wang
3 kN
AB C
D
E F
Example 1: Determine the force in members BC, CF and CG and indicate if the member is in tension or compression. Each member in the truss is 0.6 meter long.
2 kN
G
Engineering Mechanics: Statics * Dr. Yiheng Wang
3 kN
AB C
D
E F
2 kN
G
Engineering Mechanics: Statics * Dr. Yiheng Wang
Example 1: Determine the force in members BC, CF and CG and indicate if the member is in tension or compression. Each member in the truss is 0.6 meter long.
FBC FBC
FCF
FCF
FFG FFG
hint: from each segment you can solve for maximum 3 reactions.
Engineering Mechanics: Statics * Dr. Yiheng Wang
Example 1: Determine the force in members BC, CF and CG and indicate if the member is in tension or compression. Each member in the truss is 0.6 meter long.
Step 1: If necessary, determine external support reaction(s). 3 kN
AB
D
E F
2 kN
G
Dy
Dx
Ay
1.8 m
0.9 m
1.2 mC
0m9.0kN3m2.1kN2m8.1 yD AM
kN83.2 yA
Engineering Mechanics: Statics * Dr. Yiheng Wang
3 kN
AB C
D
E F
2 kN
G
Step 2: “Cut” the structure and choose one segment.
2.83 kN
Engineering Mechanics: Statics * Dr. Yiheng Wang
Step 3: Solve all unknowns. Apply rigid body equilibrium.
FBC
FCF
FFG
C
0.6 m
0.52 m
0m3.0kN 2m9.0kN 2.83
m52.0
BCF FM
0.3 m
TkN74.3 BCF
0m6.0kN 2m2.1kN 2.83
m3.0kN 3m52.0
FGC FM
CkN49.2 FGF
060cos CFFGBCx FFFF+
CkN50.2 CFF
Engineering Mechanics: Statics * Dr. Yiheng Wang
Question 1: For the following truss structure (with members AD, CD and CE all of 60
cm length each), determine the force in member BC.
(a) (b)
(c) (d)(T) N 002 (C) N 253
(T) N 141N 0
AB C
D
E
100 N
100 N
100 N 100 N
100 N
100 N
Engineering Mechanics: Statics * Dr. Yiheng Wang
(a) (b)
(c) (d)(T) N 002 (C) N 253
(T) N 141N 0
AB C
D
E
100 N
100 N
100 N 100 N
100 N
100 N
Engineering Mechanics: Statics * Dr. Yiheng Wang
Question 2: For the following truss structure (with members AD, CD and CE all of 60
cm length each), determine the force in member CD.
(a) (b)
(c) (d)(T) N 002 (C) N 253
(T) N 141N 0
AB C
D
E
100 N
100 N
100 N 100 N
100 N
100 N
Engineering Mechanics: Statics * Dr. Yiheng Wang
Question 3: For the following truss structure (with members AD, CD and CE all of 60
cm length each), determine the force in member DE.