Lately, most of my time has been consumed by coursework. As the semester winds down, I'm beginning to see the light at the end of the tunnel. One of the more interesting courses this semester is Systems Engineering. Our final team project is to build a trebuchet. It was a perfect sedgeway from my earlier post. The idea is to use system engineering tools and predictive analysis software (ie. FEA, Atreb V2.2, Minitab) to develop a robust trebuchet to satisfy customer requirements.
The course was divided into two phases:
Part I. Planning and predictive analysis
Part II.Validation, Fabrication and Testing.
Both Part I and Part II, make up what is called the System Engineering "V".
Left side is strictly design for robustness and prediction. The right side is the hardware validation and testing.
We were not allowed to build/test the treb until Part II.
The commercial software package Atreb V2.2, was tremendous, as it helped us understand the physics of a trebuchet. Although, our group is comprised of mechanical and electrical engineers. Nobody knew how the contraption worked, and I certainly wasn't born in the middle-ages. The treb operation was based upon first principles, but it clearly was non-trivial.
We used Minitab, a statistical tool, as a means to develop a sensitivity analysis, which would help validate our DOE.
We could then better understand the variability or the noise factors inherent to our design (ie. main arm pin friction, counterweight mass, main arm length).
After running Minitab, we studied the main-effects and then used this information to begin modeling the treb in CatiaV5.
Once we had a general idea how to model the package, we set out to improve robustness.