4 point loads 8,15,15,&10 KN have center to center spacing of 2m between conjugative loads and they travels a girder of 30m span from left to right with 10KN loading.

Subject : Structural Analysis 1

Topic : Influence line diagram.

Difficulty : High

1)Maximum (+ve)S.F.:-

$1^{st}$trial:-

Max+ve S.F.at C:-

$S.F_C=8\times\frac{22}{30}+15\times\frac{20}{30}+15\times\frac{18}{30}+10\times\frac{16}{30}$

$S.F_C=30.2KN$

$II^{nd}$ trial:-

In this first trial above max ordinate $\frac{22}{30}$ was not getting multiply max load 15KN So let us have another trial by keeping 15KN load

$S.F_C=10\times\frac{18}{30}+15\times \frac{20}{30}+15\times \frac{22}{30}-8\times\frac{6}{30}$

$S._C=25.4KN$

In two trial $1^{st}$one is maximum so $S.F_C$=30.2KN

Max+ve S.F=30.2KN

2.Max(-ve)$S.F_C$ …