Lecture
6 : Maxwell-Betti Law of Reciprocal Deflections
Example 4.23 Verify Maxwell-Betti law of reciprocal displacement for the rigid-jointed plane frame with reference to marked direction as shown in Figure 4.35(a). EI is same for both members.
Solution: Apply the forces and in the directions 1 and 2, respectively as shown in Figure 4.35(b).
and 
in the directions 1 and 2, respectively as shown in Figure 4.35(b). 
