SUMMARY
The discussion centers on calculating the modulus of rigidity (G) for a material using a torsion testing machine. The specimen has a diameter of 12.5mm, a torque (T) of 4.5Nm, and an angle of twist of 4.0 degrees over a gauge length of 0.75m. The polar moment of inertia (J) is calculated using the formula J = π(d^4)/32, leading to a value of J = 3.8349 x 10^-8 m^4. The final modulus of rigidity is determined to be G = 126 x 10^7 Pa, after correcting the diameter conversion from 0.025m to 0.0125m.
PREREQUISITES
- Understanding of torsion testing principles
- Familiarity with the modulus of rigidity (G) concept
- Knowledge of polar moment of inertia calculations
- Proficiency in unit conversions (mm to m)
NEXT STEPS
- Study the derivation of the polar moment of inertia formula J = π(d^4)/32
- Learn about the significance of the modulus of rigidity in material science
- Explore the effects of varying torque on the angle of twist in torsion tests
- Investigate common errors in unit conversions in engineering calculations
USEFUL FOR
Mechanical engineers, materials scientists, and students studying mechanics of materials who are involved in torsion testing and modulus of rigidity calculations.