Advanced Methods of Structural Analysis

3.5 Special Types of Trusses 65

C

A B

Hinged chain Hanger

a

C

A B

Hinged chain

b

A B

C

c

Hinged chain

Fig. 3.22 Trusses with hinged chain

The typical truss with a hinged chain located above the truss is shown in Fig.3.23.
Assume that the parameters of the structure are as follows:dD 3 m,hD 2 m,fD
7 m, andLD 24 m. We need to construct the influence lines for the reactions and
the internal forces in hanger,Vn. As usual we start with the kinematical analysis of
the structure: it shows that the structure is geometrically unchangeable and statically
determinate.

Joint n Sn

Sn–1

Vn

x

y

(tang − tana)^2 fd

Inf. line Vn

+

IL(RA)

f

−^4 d

Inf. line H

4 d

f^2 d= 0.857

f

Left portion −

(Right portion)

Connecting line

8

9 ′

9

RB

P= 1

A^3

4

5 7

RA 2 6 1

C

1

h

d

f

n

k

L=24m

a (^1) B
T
D
2
2
Vn
m
SleftSright
N
a
a
g
g
b
Fig. 3.23 Truss with a hinged chain: design diagram and influence lines