Prob lenn l Classify each of the structures as statically d

Prob lenn # l Classify each of the structures as statically determinate, statically indeterminate, or unstable. If Indeterminate, specify the degree of indeterminacy.

Solution

a) The above structure is stable as all the reactions are not parallel ( If parallel then unstable).

This is statically indeterminate beam. Degree of indeterminacy (DOI) = (2+2+1-3) = 2.

b) The above structure is stable as all the reactions are not parallel ( If parallel then unstable).

This is statically determinate beam. Degree of indeterminacy (DOI) = (1+2-3) = 0.

c)The above structure is unstable as there is only one support.

This is statically determinate beam. Degree of indeterminacy (DOI) = (2-3) = -1.

d) The above structure is unstable as it is not supported in horizontal direction. If horizontal load is applied then it wiil move to sway.

This is statically indeterminate beam. Degree of indeterminacy (DOI) = (2+2-3) = 1.