Basic Statements 7

Question 1

The warping displacement is a product of the rate of twist and the warping shape function

Answer 1

True -

u(x,y,z) = fi’(x)*w(y,z)

Question 2

The rate of twist determines the magnitude of the warping displacement while the shape function determines the shape of the warping displacement

Answer 2

True -
u = magnitude
fi’ = shape

Question 3

Th virtual work concept can be used to derive the normal stress that occurs during Vlasov torsion conditions

Answer 3

True -

Sigma = B * Omega / Iomega

Question 4

Normal and shear stresses occur in a structure subjected to pure St Venant torsion conditions

Answer 4

False - Since the rate of twist, fi’, is constant there will not be normal stresses.
Sigma = -Efi’‘w, and fi’‘=0

Question 5

The normal stress in Vlasov theory is calculated using the section force called the bimoment

Answer 5

True -

Sigma = B*Omega/Iomega

Question 6

According to Vlasov theory, the shear stress distribution is uniform through thickness for thin-walled cross-sections

Answer 6

True - Uniform for Vlasov and linear for St Venant

Question 7

Mixed torsion = either St Venant or Vlasov theory, not a combination of the two

Answer 7

False - It is a combination of the two, therefore Mixed torsion = St Venant + Venant

Question 8

A torsion parameter can be calculated to check whether mixed torsion conditions prevail or not

Answer 8

True -

alfa = GKv / EIw