WrittenTest February 13 2024

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Course of Aerospace Structures Written test, February 13 th, 2024 Name Surname Person code: Exercise 1 The semi-monocoque wing box model represented in the figure has five uniformly spaced ribs (including the rib located at the clamp) and ten stringers (five uniformly spaced on the upper side, five uniformly spaced on the lower side). Each stringer has a concentrated areaA. The panels thickness is equal to t. The wing box is loaded by a pressure load that is constant along the wing span and has a triangular distribution along the chord, with the maximum value equal top. Compute the upper right stringer jump of axial stress∆σzz across the mid-span rib. (Unit for result: MPa) Data 4l = 3 m a = 1 m b = 10 cm t = 1 mm A = 10 cm2 p = 1000 Pa Answer Exercise 2 The semi-monocoque beam model sketched in the figure has a triangular cross-section with three con- centrated areas A, two panels of thicknesst and one panel of thickness2t. The beam has length l, is clamped at one extremity and loaded by the forceF, aligned with the vertical panel, at the free extremity. Compute the overall torsional rotation of the loaded extremity section. (Unit for result: rad) Data a = 0.5 m A = 4 cm2 t = 1 mm l = 4 m E = 70000 MPa ν = 0.3 F = 10000 N Answer Exercise 3 Consider the thin beam model sketched in the figure, and loaded by the forceF applied at pointA. All the beams have the same cross-section. Compute the rotationθ of the point where the beam of lengthb is joined to the two beams of lengtha. Neglect shear deformability. (Unit for result: rad) Data a = 1 m b = 2 m c = 3 m EIxx = EIyy = 12 × 1014 N mm2 EA = 6 × 1010 N GJ = 7 × 109 N mm2 K = 1 N/mm F = 10000 N Answer Exercise 4 Consider the simply supported thin beam model sketched in the figure, with overall lengthl, and loaded by the…