Question

a shaft is subjected to fluctuating loads with nominal torque of 1500 n-m and a bending moment of 2000 n-m respectively. if the combined shock and fatigue factors for bending and torsion are 2.0 and 1.5 respectively then the equivalent torque (n-m) is

Answer 1

The equivalent torque for a shaft under nominal torque of 1500 N·m and bending moment of 2000 N·m, considering shock and fatigue factors of 2.0 for bending and 1.5 for torsion, is approximately 3061.2 N·m.

Step-by-step explanation:

To calculate the equivalent torque for a shaft subjected to fluctuating loads, we use the following formula derived from the theory of combined stresses: Teq = √(Tn2 + (Mn km / kt)2)

{ where Teq is the equivalent torque, Tn is the nominal torque, Mn is the nominal bending moment, km is the combined shock and fatigue factor for bending, and kt is the combined shock and fatigue factor for torsion.}

In this case, we have:

• Tn = 1500 N·m (Nominal Torque)
• Mn = 2000 N·m (Nominal Bending Moment)
• km = 2.0 (Shock and Fatigue Factor for Bending)
• kt = 1.5 (Shock and Fatigue Factor for Torsion)

Plugging these values into our formula, we get:

Teq = √(15002 + (2000 * 2.0 / 1.5)2)

Teq = √(2250000 + (4000 / 1.5)2)

Teq = √(2250000 + 7111111.11)

Teq = √(9361111.11)

Teq = 3061.2 N·m

So, the equivalent torque is approximately 3061.2 N·m.