The cross sections of two hollow bars made of the same material are concentric circles as shown in the figure. It is given that r_{3} > r_{1} and r_{4} > r_{2} , and that the areas of the cross-sections are the same. J1 and J2 are the torsional rigidities of the bars on the left and right, respectively. The ratio J2/J1 is
Consider a stepped shaft subjected to a twisting moment applied at B as shown in the figure. Assume shear modulus , G = 77 GPa. The angle of twist at C (in degrees) is _____
$\frac{?}{r}=\frac{T}{J}=\frac{G.\theta}{l}\phantom{\rule{0ex}{0ex}}angleoftwist@C=angleoftwist@B\phantom{\rule{0ex}{0ex}}\frac{T}{J}=\frac{G.\theta}{l}\phantom{\rule{0ex}{0ex}}?\theta =\frac{T.l}{G.J}\phantom{\rule{0ex}{0ex}}=\frac{10\times 0.5}{77\times {10}^{9}\times \mathrm{\pi}/32\times 0.{02}^{4}}\phantom{\rule{0ex}{0ex}}=4.133\times {10}^{-3}\phantom{\rule{0ex}{0ex}}=0.{1368}^{\xb0}$
A hollow shaft of 1 m length is designed to transmit a power of 30 kW at 700 rpm. The maximum permissible angle of twist in the shaft is 1^{o}. The inner diameter of the shaft is 0.7 times the outer diameter. The modulus of rigidity is 80 GPa. The outside diameter (in mm) of the shaft is _______.
A torque T is applied at the free end of a stepped rod of circular cross-sections as shown in the figure. The shear modulus of the material of the rod is G. The expression for d to produce an angular twist θ at the free end is
A solid shaft of diameter, d and length L is fixed at both the ends. A torque, T_{0} is applied at a distance, L/4 from the left end as shown in the figure given below.
The maximum shear stress in the shaft is
A solid circular shaft of diameter 100 mm is subjected to an axial stress of 50 Mpa. It is further subjected to a torque of 10 kNm. The maximum principal stress experienced on the shaft is closest to