User:Eas4200c.f08.gator.edwards/Airfoil

The goal of this week's addition to the MATLAB program is to determine the buckling strength of the airfoil skin. Only the sections of skin between the stringers were considered, that is sections BF and EH. The load conditions remained My = -125 kN.cm and Mz = 50 kN.cm.

Next the provided Excel file was used to find ultimate stresses for varying aspect ratios. These were plotted with the maximum stress found in the Matlab program. The idea is that since the airfoil skin is not clamped or simply supported but somewhere in between so the maximum normal stress should lie between the two curves taken from the Excel file.

It is clear that the maximum stress is outside the boundaries of the curves. This means that the skin alone cannot stand up to the bending moments applied and will buckle unless it is reinforced by stringers.