WORLD FOR CIVIL

Statics & Strength of Materials

Topic 6.4a - Problem Assignment 1 - Torsion

1. A 3 inch diameter solid steel shaft is 15 inches long. A torque of 750 inch pounds is applied to the shaft. Determine the maximum shear stress in the shaft. Where does the maximum shear stress occur. (142 psi., outer radius)

2. A vice is clamped by applying a force of 50 pounds at each end of a 4 inch arm on a shaft. The shaft is solid 3/8 inch diameter steel. Determine the maximum shear stress in the shaft. (19,320 psi)

3. A C-clamp is tightened by applying a couple (equal forces in opposite directions on opposite sides) to a 3" diameter lever at the end of the clamp screw. The clamp screw is effecively a 5/16 inch diameter steel shaft. The maximum allowable shear stress in the shaft is 8000 psi. Find the maximum force that can be applied in the couple. (16 lb)

4. The drive shaft of a car is a hollow steel shaft with an outside diameter of 3 inches and a wall thickness of 1/8 inch. Determine the polar section modulus of the shaft. What is the maximum shear stress in the shaft when it has a torque applied equal to 2200 inch pounds. (2.34 in⁴, 1410 psi)

5. A 3/4 inch solid steel shaft is 8 inches long. The maximum allowable stress for the shaft is 12,000 psi. Determine the maximum torque that can be transmitted by the shaft. What is the angle of twist for the shaft? G= 12x10⁶ psi. (82.84 ft-lb, .0213 rad)

6. A 1/32 inch twist steel drill has a torque of 0.1 inch pounds applied. The free length of the drill is 2 inches long. Find the maximum torsional stress in the drill. Determine the angle of twist of drill. (16.7 x 10³ psi, .178 rad)

7. The steel drive shaft of a car has a torque applied of 1600 inch pounds. The drive shaft is 4 feet long and 2.5 inches in diameter with a 1/16 diameter wall thickness. Determine the maximum shear stress in the shaft and the angle of twist. (5415 psi, .01733 rad)

8. A hollow steel shaft 2 inches in diameter and 3 feet long with 1/16 inch walls is used in an auger. Determine the angle of twist of the shaft when a torque of 5000 inch pounds is applied to one end of the shaft. What is the maximum shear stress in the shaft? (.042 rad, 13, 990 psi)

9. A three foot wooden dowel 1/4 inch in diameter has a torque of 5 inch pounds applied. Determine the angle of twist of the dowel and the maximum shear stress in the wood. G = 1.04x10⁶ psi. (1630 psi, .4513 rad)