Structural Analysis of a Pedal-Powered Maize Sheller
In Ghana, maize is one of the highest-yielding cash crops, but the supply chain is severely hampered by the lack of access to machines for processing. This study conducts a structural analysis on a low-cost, pedal-powered maize sheller, designed and fabricated by the author and found to operate with a high shelling rate and low kernel damage. To inform an improved iteration of the design, structural analysis was carried out along the lines of reliability of the bearing that was used, factor of safety for both static and fatigue loads, weight optimization, and trend forecast for shelling performances. Using a reliability of 90%, a 180409 Instrument Precision ball bearing was calculated to have a life cycle of 3468.44 hrs which fell in the range needed for agricultural equipment. Moreover, the static and fatigue analysis revealed yield strength values that were higher than the applied stresses. As such, they were deemed safe, except for the bicycle cleats, which needed fillets to reduce stress concentrations. From the weight optimization, it was determined by the author that one-fourth of the cylinder stand's weight can be removed to save on material without hampering the assembly's structural integrity. Lastly, using a forecast of shelling trends, a trade-off was discovered between kernel damage and shelling rate.
Capstone Project submitted to the Department of Engineering, Ashesi University in partial fulfillment of the requirements for the award of a Bachelor of Science degree in Mechanical Engineering, May 2021
Aggrey, O.A. (2021). Structural Analysis of a Pedal-Powered Maize Sheller. Applied project, Ashesi University, Berekuso. 55pgs.