## Machine Design Miscellaneous

#### Machine Design

1. The bolts in a rigid flanged coupling connecting two shafts transmitting power are subjected to

1. NA

##### Correct Option: A

NA

1. The bolts in a rigid flanged coupling connecting two shafts transmitting power are subjected to

1. NA

##### Correct Option: A

NA

1. Stress concentration in a machine component of a ductile material is not so harmful as it is in a brittle material because

1. Local yielding reduces stress concentration effect.

##### Correct Option: A

Local yielding reduces stress concentration effect.

1. In a bolted Joint two smooth members are connected with an axial tightening force of 2200 N. If the bolt used has metric threads of 4 mm pitch, the torque required for achieving the tightening force is

1. Tightening force = 2200 N
Pitch = 4 mm = 0.004 m

 Torque = Tightening force × 0.004 = 1.4 N-m 2π

##### Correct Option: C

Tightening force = 2200 N
Pitch = 4 mm = 0.004 m

 Torque = Tightening force × 0.004 = 1.4 N-m 2π

1. A bolted Joint is shown below. The maximum shear stress, in MPa, in the bolts at A and B, respectively are

1.  FA = FB = FC = 10 kN 3

 FA = P.e.r = 10 × 103 × 150 × 40 rA² + rB² + rC² 40² + 0² + 40²

F'A = 18.75 kN = F'C
Shear load at A and C
FR = √(FA)² + (F'A = √(3.33)² + (18.75)²
FR = 19.04 KN
 τmax = 19.04 × 103 (π / 4) × 102

( τmax )A,C = 242.5 MPa
( τmax )B = 42.44 MPa

##### Correct Option: A

 FA = FB = FC = 10 kN 3

 FA = P.e.r = 10 × 103 × 150 × 40 rA² + rB² + rC² 40² + 0² + 40²

F'A = 18.75 kN = F'C
Shear load at A and C
FR = √(FA)² + (F'A = √(3.33)² + (18.75)²
FR = 19.04 KN
 τmax = 19.04 × 103 (π / 4) × 102

( τmax )A,C = 242.5 MPa
( τmax )B = 42.44 MPa