Example

Classify each of the structures shown in Fig. 3.15 as externally unstable, statically determinate, or statically indeterminate.
If the structure is statically indeterminate externally, then determine the degree of external indeterminacy.

Solution
(a) This beam is internally stable with r = 5 > 3. Therefore, it is statically indeterminate externally with the degree of external indeterminacy of