UFMFX6-15-2-Aero Structures

Assignment

Figure 1 illustrates a typical AAI RQ-7 Shadow Unmanned Aerial Vehicle (UAV). For the sake of simplicity, it is assumed that the aerofoil shape of UAV has the profile given in Figure 2, i.e. it constitutes of two closed sections and one open section. The length of each wing is  meters in which  is the last two digits of your student ID (for example, for student ID of 123456789 is 89).

As the result of a bird impact to the tip of the wing, an upward shear force of  kN and an anticlockwise torque of  kNm is imposed on the wing structure (see Figure 1). The wing is made up of material having shear modulus  of 25,000N/mm2. Address the following questions at a wing location 1m away from the root of the wing;

a)Calculate maximum direct stress as the result of bending in the section imposed by the bird strike.

b)Calculate the shear stress at the midpoint of web 36 as the result of shear loading only, imposed by the bird strike.

c)Calculate the rate of twist of the section and the maximum shear stress as the result of torsional loading imposed by the bird strike.