Find the axial forces at CG, DH, GH, BC, and BG in the truss shown below: 2m 2m 2m 2m C B D 1m E 1m A F G H 15 KN 20 KN 15 KN

Structural Analysis
6th Edition
ISBN:9781337630931
Author:KASSIMALI, Aslam.
Publisher:KASSIMALI, Aslam.
Chapter2: Loads On Structures
Section: Chapter Questions
Problem 1P
icon
Related questions
Question

SHOW GIVEN, DIAGRAM, SOLUTIONS, AND FINAL ANSWER :)

*Draw and label the parts of a typical truss.

 

I attached an example for a guide 

Find the axial forces at CG, DH, GH, BC, and BG in the truss shown below:
2m
2m
2m
2m
D
1m
B
E
1m
A
F
G
H
15 KN
20 KN
15 KN
Transcribed Image Text:Find the axial forces at CG, DH, GH, BC, and BG in the truss shown below: 2m 2m 2m 2m D 1m B E 1m A F G H 15 KN 20 KN 15 KN
IENTIA
HENTIA
Examples:
1. Find the axial forces in the members of the truss shown.
Given:
EDIFICAL
The FBD of joint A is constructed and the forces in
members AB and AC are obtained. (Always assume the
unknown member forces acting on the joint's FBD to be in
tension).
+1.2 m + 1.2 m→→+1.2 m → 1.2 m
AB
C
+t ΣV 0
VER
|0.9 m
В
D
e) (AB) = 0
10.5 +
E
[0.9 m
A
AF
negative sign means that the member
AB = 17.5 kN (C)
АВ — —17.5 kN
A
F
G
H
is in compression.
000
+→ EH = 0
6 kN
9 kN
6 kN
Av = 10.5 kN
AF + (E) (AB) = 0
substitute the computed value of AB.
Required: Force in each member of the truss
Solution:
AF +
E)(-17.5) = 0
AF = 14 kN (T)
Solve for the reactions by constructing a free diagram of the truss and using the equations
of equilibrium.
AF = 14 kN
BF
Joint F is isolated next. (It is not advisable to isolate joint B
at this stage since there are three unknown forces acting
on B.)
+1.2 m →+ 1.2 m→|+ 1.2 m →+ 1.2 m→
C
В
D
|0.9 m
FG
+1 ΣV - 0
F
E
0.9 m
AF = 14 kN
BF – 6 = 0
Ан
BF = 6 kN
BF = 6 kN (T)
EDIFICA
F
G
H
V 6 KN
+-ΣΗ 0
FG – 14 = 0
6 kN
9 kN
6 kN
CHY
Av
RE
FG = 14 kN
FG = 14 kN (T)
Joint B can now be isolated and only two unknowns will
appear in the FBD since the forces AB and BF are already
known.
ВС
%3D
Since tan-1
= 36.87°, then angle 0 = 2(36.87°) = 73.74º
AĦ = 0
B.
+ ΣΥ= 0
+u £ Mg
-BG sin 73.74° – 6 cos 36.87° = 0
A, (4.8) – 6(3.6) – 9(2.4) – 6(1.2) = 0
4
-
AB=17.5 kN
BG
BG = -5 kN
BG = 5 kN (C)
Ay = 10.5 kN ↑
BF=6 kN
+7 EX = 0
+u £MA
17.5 + BC – 6 sin 36.87° + BG cos 73.74° = 0
-RE (4.8) + 6(3.6) + 9(2.4) + 6(1.2) = 0
17.5 + BC – 6 sin 36.87° + (-5) cos 73.74° = 0
RE = 10.5 kN ↑
ВС %3D —12.5 kN
BC = 12.5 kN (C)
SITY
Transcribed Image Text:IENTIA HENTIA Examples: 1. Find the axial forces in the members of the truss shown. Given: EDIFICAL The FBD of joint A is constructed and the forces in members AB and AC are obtained. (Always assume the unknown member forces acting on the joint's FBD to be in tension). +1.2 m + 1.2 m→→+1.2 m → 1.2 m AB C +t ΣV 0 VER |0.9 m В D e) (AB) = 0 10.5 + E [0.9 m A AF negative sign means that the member AB = 17.5 kN (C) АВ — —17.5 kN A F G H is in compression. 000 +→ EH = 0 6 kN 9 kN 6 kN Av = 10.5 kN AF + (E) (AB) = 0 substitute the computed value of AB. Required: Force in each member of the truss Solution: AF + E)(-17.5) = 0 AF = 14 kN (T) Solve for the reactions by constructing a free diagram of the truss and using the equations of equilibrium. AF = 14 kN BF Joint F is isolated next. (It is not advisable to isolate joint B at this stage since there are three unknown forces acting on B.) +1.2 m →+ 1.2 m→|+ 1.2 m →+ 1.2 m→ C В D |0.9 m FG +1 ΣV - 0 F E 0.9 m AF = 14 kN BF – 6 = 0 Ан BF = 6 kN BF = 6 kN (T) EDIFICA F G H V 6 KN +-ΣΗ 0 FG – 14 = 0 6 kN 9 kN 6 kN CHY Av RE FG = 14 kN FG = 14 kN (T) Joint B can now be isolated and only two unknowns will appear in the FBD since the forces AB and BF are already known. ВС %3D Since tan-1 = 36.87°, then angle 0 = 2(36.87°) = 73.74º AĦ = 0 B. + ΣΥ= 0 +u £ Mg -BG sin 73.74° – 6 cos 36.87° = 0 A, (4.8) – 6(3.6) – 9(2.4) – 6(1.2) = 0 4 - AB=17.5 kN BG BG = -5 kN BG = 5 kN (C) Ay = 10.5 kN ↑ BF=6 kN +7 EX = 0 +u £MA 17.5 + BC – 6 sin 36.87° + BG cos 73.74° = 0 -RE (4.8) + 6(3.6) + 9(2.4) + 6(1.2) = 0 17.5 + BC – 6 sin 36.87° + (-5) cos 73.74° = 0 RE = 10.5 kN ↑ ВС %3D —12.5 kN BC = 12.5 kN (C) SITY
Expert Solution
steps

Step by step

Solved in 4 steps with 4 images

Blurred answer
Knowledge Booster
Steel framing
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Structural Analysis
Structural Analysis
Civil Engineering
ISBN:
9781337630931
Author:
KASSIMALI, Aslam.
Publisher:
Cengage,
Structural Analysis (10th Edition)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Principles of Foundation Engineering (MindTap Cou…
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
Fundamentals of Structural Analysis
Fundamentals of Structural Analysis
Civil Engineering
ISBN:
9780073398006
Author:
Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:
McGraw-Hill Education
Sustainable Energy
Sustainable Energy
Civil Engineering
ISBN:
9781337551663
Author:
DUNLAP, Richard A.
Publisher:
Cengage,
Traffic and Highway Engineering
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning