Compare the results of Problem P13.20 (a) and (c) with Problem P13.21(a) and (c).

Problem P13.20

Computer Study—comparison of approximate analysis with an exact analysis. (a) Use approximate analysis to compute the reactions and draw the moment diagrams for column AB and girder BC of the frame in Figure P13.20, and draw the deflected shape. Consider column bases are fixed. (b) Repeat the computations with pinned column bases at A and D. (c) Compare the results with the exact analysis using a computer software. Consider columns A = 13.1 in.2, I = 348 in.4; girder A = 16.2 in.2, I = 1350 in.4. Use E = 29,000 kips/in.2 for all members.

Problem P13.21

Computer Study—comparison of approximate analysis with exact analysis. Consider the structures in Figures P13.21, respectively. (a) Use approximate analysis to compute the reactions and draw moment diagram for the column AB and draw the approximate deflected shape of the frame. (b) Determine truss bar forces. All truss joints are pinned. (c) Compare the results with the exact analysis using a computer software. Truss member properties are A = 4 in.2, columns A = 13.1 in.2, I = 348 in.4 and E = 29,000 kips/in.2 for all members.