ME or MEng Master of Engineering Master of Engineering Machine Design 2

Question 1

A shaft experiences a bending moment of 500 N·m and a torque of 300 N·m. Using the von Mises criterion, what is the equivalent bending moment?

Accepted Answer

583 N·m

Answer

The equivalent moment by von Mises is √(M² + 0.75T²) = √(500² + 0.75×300²) ≈ 583 N·m.

Question 2

In a bolted joint subjected to an external tensile load, the joint stiffness constant C is defined as:

Accepted Answer

kb/(kb + km)

Answer

C = kb/(kb + km) represents the fraction of external load carried by the bolt, where kb is bolt stiffness and km is member stiffness.

Question 3

Which failure theory is most appropriate for designing ductile machine components under static loading?

Accepted Answer

Von Mises (Distortion Energy) Theory

Answer

The Distortion Energy Theory (von Mises) best predicts yielding in ductile materials and is the most accurate for static loading.

Question 4

A helical compression spring has a spring index C = 8. What is the Wahl correction factor (approximately)?

Accepted Answer

1.18

Answer

The Wahl factor Kw = (4C−1)/(4C−4) + 0.615/C = (31)/(28) + 0.077 ≈ 1.18 for C = 8.

Question 5

In gear design, the AGMA service factor Ks accounts for:

Accepted Answer

Size effects on material strength

Answer

The AGMA size factor Ks reflects the reduction in material strength with increasing tooth and gear size.

ME or MEng Master of Engineering Practice Test