(Solved): solve all 3. The rigid jointed plane frame shown in Figure 3 is fixed at joint 1 and pinned at joint ...

3. The rigid jointed plane frame shown in Figure 3 is fixed at joint 1 and pinned at joint 4. Initially the frame is also propped by a column at joint 3 (assume there is no rotational fixity between the column and the rest of frame). The frame is subject to a vertical point load of 90kN. The flexural rigidity of each member is also shown in Figure 3. a) Determine the bending moments at each joint of the frame. (3 marks) b) If the column support at joint 3 becomes damaged and no longer provides support to the frame at that location. Use the moment distribution method to determine the bending moment at each joint. (18 marks) c) Draw the bending moment diagram in the absence of the supporting column. (4 marks) 4m 90KN 2 5m J k 3EI 4EI 5m Figure 3 3EI 3 3m