Aerospace Vehicle Structures - II Mid - II, November - 2014

1.To idealize the panel, the assumption should be all direct stresses are carried by --------
  • Skin panels
  • Booms
  • Web
  • None
Answer: B
2.The direct stress distribution in the actual panel varies -------- from an unknown value σ1 to an unknown value σ2
  • Parabolic
  • Hyperbolic
  • Linear
  • Cubic
Answer: C
3.There are ------- direct stresses are developed in either open or closed section beams subjected to a pure torque unless axial constraints are present
  • More
  • Less
  • Equal
  • No
Answer: D
4.The large number of closely spaced stringers allows the assumption of a ------- shear flow in the skin between adjacent stringers.
  • Constant
  • Linear
  • Non-uniform
  • None
Answer: A
5.If the shear loads applied through the shear center of any section, the rate of twist is—
  • Minimum
  • Zero
  • Constant
  • Maximum
Answer: B
6.The shear stress distribution at the built-in end of a closed section beam is statically ---
  • Indeterminate
  • Determinate
  • Equilibrium
  • Non-equilibrium
Answer: B
7.The resultants of the internal shear flows q must be --------- to the applied loading
  • Statically equivalent
  • Zero
  • Unequal
  • None
Answer: A
8.The free warping distribution for thin-walled rectangular section is ------ around the cross-section and ----- along the length of the beam.
  • Nonlinear, Uniform
  • Linear, Non-uniform
  • Linear, Uniform
  • Nonlinear, Non-uniform
Answer: C
9.The shear strains in the thin walls of beams subjected to ------- cause cross-sections to distort or warp
  • Shear loads
  • Bending loads
  • Torsion
  • Axial loads
Answer: A
10.If a beam is axially unconstrained and loaded by a pure torque τ the rate of twist is ---------- along the beam
  • Zero
  • Constant
  • Linear
  • Nonlinear
Answer: B
11.If the difference between the distances of the stringer centroids and the adjacent skin from the wing section axis is small, we can assume that the direct stress is ---------------------- over the stringer cross-sections.
Answer: Constant
12.For structural idealization, to replace the stringers and spar flanges by concentrations of area is known as ------------------------
Answer: Booms
13.For structural idealization, in wing and fuselage sections, the skin is effective mainly in resisting ---------------------------- stresses
Answer: Shear
14.The position of the neutral axis is derived from the condition that the resultant load on the beam cross-section is -------------------------------
Answer: Zero
15.The point where a shear force can act without producing any twist in the section (In general not the centroid, but a point through which a force transverse to the axis of a beam section can act and not cause any twisting of the beam section) is called ------------------------
Answer: Shear Center
16.Shear force per unit length is called -----------------------------------
Answer: Shear flow
17.Torsion-bending constant is purely a function of the -----------------------------------
Answer: Geometry of the cross-section
18.Conventional Plane Beam Theory underestimates the -------------------- effects for thin-walled box beam.
Answer: Shear lag
19.The chordwise pressure distribution on an aerodynamic surface may be represented by --------------- loads acting through the aerodynamic center together with a pitching moment.
Answer: Shear
20.If the wing section is completely idealized, lift and drag loads induce ----------------- in the skin panels, which are constant between adjacent booms.
Answer: Shear flows