Deck 9: Torsion

Question 1

A motor drives a shaft at f 5 10 Hz and delivers P 5 35 kW of power. The allowable shear stress in the shaft is 45 MPa. The minimum diameter of the shaft is approximately:
(A) 35 mm
(B) 40 mm
(C) 47 mm
(D) 61 mm

Answer 1

B

Question 2

A motor drives a shaft with diameter d 5 46 mm at f 5 5.25 Hz and delivers P 5 25 kW of power. The maximum shear stress in the shaft is approximately:

Answer 2

B

Question 3

steel tube with diameters 5 52 mm is twisted by torques at the ends. The diameter of a solid steel shaft that resists the same torque at the same maximum shear stress is approximately:
(A) 56 mm
(B) 62 mm
(C) 75 mm
(D) 82 m.m

Answer 3

D

Question 4

brass pipe is twisted by torques T 5 800 N ? m acting at the ends causing an angle of twist of 3.5 . The pipe has the following properties: 56 mm. The shear modulus of elasticity G
Of the pipe is approximately:

Question 5

angle of rotation between the ends of a nylon bar is . The bar diameter is 70 mm and the allowable shear strain is 0.014 rad. The minimum permissible length of the bar is approximately:
(A) 0.15 m
(B) 0.27 m
(C) 0.40 m
(D) 0.55 m

Question 6

brass bar twisted by torques T acting at the ends has the following properties: and 41 GPa. The torsional stiffness of the bar is approximately:

Question 7

aluminum bar of diameter 52 mm is twisted by torques at the ends. The allowable shear stress
(A) 1450 N ? m
(B) 1675 N ? m
(C) 1710 N ? m
(D) 1800 N . m

Question 8

brass rod of length L 5 0.75 m is twisted by torques T until the angle of rotation between the ends of the rod is 3.5 . The allowable shear strain in the copper is 0.0005 rad. The maximum permissible diameter of
The rod is approximately: S
(A) 6.5 mm
(B) 8.6 mm
(C) 9.7 mm
(D) 12.3 mm

Question 9

gear shaft transmits torques the allowable shear stress is 50 MPa, the required shaft diameter is approximately:
(A) 38 mm
(B) 44 mm
(C) 46 mm
(D) 48 mm

Question 10

A hollow aluminum shaft ( 52 mm) has an angle of twist per unit length of 1.8° /m due to torques T. The resulting maximum tensile stress in the shaft is approximately:

Question 11

Torques T 5 5.7 kN ∙ m are applied to a hollow aluminum shaft ( allowable shear stress is 45 MPa and the allowable normal strain is 8.0 . The required outside diameter of the shaft is approximately:
(A) 38 mm
(B) 56 mm
(C) 87 mm
(D) 91 mm

Question 12

Bending stresses, combined stress, composite sections
(A) 0.9
(B) 1.2
(C) 1.4
(D) 2.1

Question 13

stepped steel shaft ( 32 mm is twisted by torques T at each end. Segment lengths are 0.75 m. If the allowable shear stress is 28 MPa and
Maximum allowable twist is 1.8°, the maximum permissible torque is approximately:

Question 14

stepped steel shaft with diameters m and m acting in opposite directions. The maximum shear stress is approximately:

Question 15

A drive shaft running at 2500 rpm has outer diameter of 60 mm and inner diameter of 40 mm. The allowable shear stress in the shaft is 35 MPa. The maximum power that can be transmitted is approximately:
(A) 220 kW
(B) 240 kW
(C) 288 kW
(D) 312 kW