Type of Breakage The structure broke through the middle. -‐ With the plywood failing to carry the shear, the load was primarily carried by the compression chord -‐ Did not fracture at knot because of its strategic placement -‐ Did not fracture where screws were inserted
Figure 8: The breakage of the structure.
Discussion:
Figure 9: Load path with joined members
The structure would have held a greater load if there was no gap between the two pieces of pine; if they were joined (Figure 9). The screw in the knot (Figures 10, 11) made the point of weakness even weaker. The structure was oriented such that the knot was placed in the area of the beam in compression (Figure 12), so that it would Figure 10: The be less likely to fracture. knot
Figure 11: A screw w as Figure 12: Knots should be inserted into a knot in one of the placed at the top of a beam pieces of pine.
Figure 13: A greater load can be supported w ith greater height as opposed to greater width.
The structure was oriented vertically so the load had the most medium to travel through (Figure 13).