UCI Cargo Plane - Structural Optimization
Background
The International SAE Aero organization has decreased the maximum allowable wingspan for this year’s competition. Also, UCI Cargo Plane will be incorporating a fuselage frame this year. These new issues will require new design and stress analysis on the structural elements of the plane, primarily the cargo bay section of the fuselage and the primary spar. Therefore, we have re-designed and tested these structures to withstand aerodynamic loads while minimizing weight.
Goal and Objectives
Our goal is to provide mathematically driven design of the cargo bay fuselage beam and the primary spar through hand calculations, FEA analysis and static testing. Material research was first conducted to determine the material with the highest strength to weight ratio, allowing us to select spruce for our caps and balsa for our shear webs.
For the cargo bay fuselage beam, FEA analysis was conducted for the the aircraft in flight, assuming point-force loading and three cases of boundary conditions, yielding a max principal stress less than the yield strength of the cargo bay fuselage beam. Since the structure is not slender and therefore calls for no worry about buckling, this analysis confirms the structural integrity of our design. The spars were sized using Femap by modeling aerodynamic loads approximated with Shrenk’s distribution along the span and using XFLR5 polars to approximate the chordwise distribution, then using optimization to find the minimum cap widths and thicknesses that would withstand the applied loading.
A real-life static testing of the primary spar done through a cantilever beam undergoing distributed force will be performed to mimic the distributed lift force during flight. The maximum deflection result from the FEA analysis is compared to the measured maximum deflection during the static testing experiment to confirm the accuracy of the analysis.
Team Contract
Christopher Park - cjpark4@uci.edu
Nathan Lang - nalang@uci.edu
Sponsor
John Larue - jclarue@uci.edu
