(Answered): 2. The rigid-jointed plane frame ABCD shown in Fig. 2 below is fully-fixed at A and pinned at D. Co ...

2. The rigid-jointed plane frame ABCD shown in Fig. 2 below is fully-fixed at A and pinned at D. Confirm that the structure is statically indeterminate to the second degree, and by introducing pins (moment releases) at joints B and C, use the Force Method to calculate the bending moments at A, B, C and directly undemeath the loaded points. Draw the bending-moment diagram for the frame. Only deformations due to bending are to be considered. The flexural rigidities of members AB, BC and CD are El, 3E1 and 2EI respectively, where El ?40x10, kN/m". Hint: The conditions of compatibility are that the relative rotations of adjacent members at joints B and C must be zero. Answers: Bending moments: M-46.1 kNm; M,-3.3 kNm; Mel-107.2 kNm; IMD?:0kNm; IM|-197.7 kNm (under the 128kN point load); IM|-124.3 kNrn (under the 5OkN point load) 8 128RN 8 3ET 4m EI t.4m 3m, 5m FIG. 2