Module 4 : Deflection of Structures
Lecture 3 : Principle of Virtual Work
 

Example 4.13 Determine vertical deflection and rotation of point B of the beam shown in Figure 4.19(a). The beam is subjected to a couple at C .

 
  
 

Solution: Vertical deflection of B : Apply a unit load at B as shown in Figure 4.19(b). Consider any point X at a distance of x from C

 
(0< x < a + b )
  (0< x < b )
=

(b < x < a + b )

The vertical deflection of point B is given by

                                                      
 
 
 
                        (i.e. in the upward direction)
 
 

Rotation of B : Apply a unit couple at B as shown in Figure 4.19(c). Consider any point X at a distance of x from C

 
 
(0< x < a + b )
  (0< x < a + b )
   
 

The rotation of point B is given by