$2.$ An indeterminate truss is loaded as shown in figure below. In addition to loads, there is an

increase of temperature of $500$

C on members AG$,$ GF and DF$.$ No change in temperature of other

members. It is also found that member BC is $10$ mm too short. Use Force Method of analysis

and determine member force in member BF of the truss. Take coefficient of thermal expansion,

$\backslash$alpha $=1\mathrm{.}08(10-5$

$)/$o

C$.$ Consider E $=200$ GPa and Cross$-$sectional area, A $=300$ mm $2$ for all members.

$($Ans: F BF $=7\mathrm{.}04$ kN $($compression$))$

D

E

A

FGH

B C

$20$ kN$50$ kN

$3$ m $3$ m

$4$ m

$3$ m