The goal of this effort was to build an analysis tool for aircraft wings and incorporate it into a program that optimizes the wing structure for the lowest weight for the conceptual design phase. The analysis tool calculates the internal stresses in primary load carrying members using established analysis methods for semimonocoque beams. Via a Graphical User Interface (GUI) built in MATLAB, the user can define the structural layout and material properties of the load carrying members. The program requires a degenerate geometry model built with Vehicle Sketch Pad (OpenVSP) to define the outer mold line (OML) of the wing, and a section of the program in MATLAB calculates the geometric parameters of the wing structure based on the model and user inputs in the GUI. Another section generates a lift curve using a Schrenk distribution, the vehicle weight, and load factors as defined by the user. The GUI also allows the user to define other external loads in addition to the aerodynamic loads. With the loads and structural model defined, the program uses the analysis tool to find a minimum structural weight while maintaining positive structural margins for all structural members. The analysis tool was compared against examples in structural analysis books from Bruhn and Peery to validate the method. The average relative difference between the normal and shear stresses calculated by the tool and the sources was 1.6%. To test the program, a Cessna 210G wing was modeled in the program and using Finite Element software. The comparison showed the tip deflection of the MATLAB model was 1.4 times that of the Finite Element Model. When the areas of the structural members were multiplied by 1.4, the normal stress in the stiffeners had an average difference of 5.8 ksi and the shear stresses in the webs had an average difference of 0.33 ksi. The program estimated the weight to be 198 lbs, underestimating the weight when compared to other existing methods.
| Identifer | oai:union.ndltd.org:CALPOLY/oai:digitalcommons.calpoly.edu:theses-3555 |
| Date | 01 December 2019 |
| Creators | Barton, Kevin M |
| Publisher | DigitalCommons@CalPoly |
| Source Sets | California Polytechnic State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Master's Theses |
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