Mechanical Engineering Concepts Quiz

What are the advantages of using the involute curve for the profile of gear teeth?

• It allows for conjugate action (constant speed ratio while gears are meshing)

• The direction of contact force does not change (reduces vibration)

• No change in speed ratio even when the center distance changes

• False

What information can you not obtain from a uniaxial tensile test?

• MSS=1/2(tensile strength)

• Stress concentration factor

• Fracture toughness

• 700

What factors must be considered when modifying the endurance limit measured from rotating polished beam tests?

• Surface condition

• Temperature

• Size

• Type of loading

• Reliability

Failure theories for brittle materials

• Max normal stress

• Brittle columb-mohr

• Modified mohr

Failure theories for ductile materials

• Max shear stress

• Distortion energy

• Ductile columb-mohr

What information can we obtain from a uniaxial tensile test?

• Yield strength

• Amount of work hardening

• Ultimate tensile strength

• Toughness

The main mechanism of plastic deformation in ductile metals is the motion of

(a)  

What is the contact ratio for spur gears?

(a)  

What is the contact ratio for helical gears?

(a)  

If a normal stress of 100MPa is applied to a tensile specimen, the maximum shear stress developed in the specimen is 100MPa.