Final Beam Report
ENGR&225
Johnson, Osborn
Introduc�on
Using one 11.9” by 19.9” board of pressboard and glue, our group set out to design a beam that
could be subjected to a three-point bend test, which would span a 25 cm gap and not exceed 10 cm in
width. The overall goal was to maximize the strength of the beam, as well as material efficiency. We
designed our beam in OnShape and used parameterized calcula�ons to determine ini�al performance
es�mates. Picture below (fig(1)) is our final design choice, which priori�zed double panes of wood on the
botom to add strength when the beam was subjected to tension during the bend test. We also used a
laser joint and wood glue to assemble the beam.
Figure 1 – Beam Model
1
Final Beam Report
ENGR&225
Johnson, Osborn
Figure 2 - Beam Drawing
Calcula�ons
Figure 3A - Parameterized Calculations 1 of 2
Figure 3B Parameterized Calculations 2 of 2
2
Final Beam Report
ENGR&225
Johnson, Osborn
Figure 4 Final Calculations Using Data
3
Final Beam Report
ENGR&225
Johnson, Osborn
Figure 5 Data Analysis
4
Final Beam Report
ENGR&225
Johnson, Osborn
Plots
Figure 6 Plot of Load (N) v Deflection (mm)
5
Final Beam Report
ENGR&225
Johnson, Osborn
Conclusion
Our belief is that our beam design had several notable shortcomings. The first of which is that
we underu�lized the material available to us. We used slightly over half of the material available, in the
future it would be ideal to determine the maximum height for each beam pane and set this as the height
dimension for the beam. This would maximize the moment of iner�a value in the bending moment
equa�on, thereby yielding a stronger design. The second is that our beam could have had more panes on
the botom because the failure was observed to occur in tension. Our beam overall was rela�vely
efficient, with an efficiency of 9.66.
6