- σ_1 is the only stress to use to find the factor of safety by the maximum normal stress theory of failure
- True
- False

- A load is changing on a part from 1,000 lb to 5,000 lb, the average and range loads are
- 6,000 lb and 4,000 lb
- 5,000 lb and 1,000 lb
- 3,000 lb and 2,000 lb
- 1,000 lb and 5,000 lb

- A part is loaded under service stress for 25,000 reversals, then under a higher stress for 35,000 reversals until failure. If the total life under the larger stress alone is 36,000 reversals, what is the estimated life under the service load?
- 900,000 reversals
- 37,000 reversals
- 50,000 reversals
- 60,000 reversals

- Brittle materials fail in yielding
- True
- False

- By applying 10,000 in.lb torque to this non-rotating shaft, the torque reactions are
- T1=5,000 in.lb; T2=5,000 in.lb
- T1=6,000 in.lb; T2=4,000 in.lb
- T1=4,000 in.lb; T2=6,000 in.lb
- None of the above

- For a ductile material, the yield stress in shear is the same as it is for tension
- True
- False

- For a loaded part, the state of stress is σ_x=2,000 psi, σ_y=-8000 psi, τ_xy=0. If σ_yp=45,000 psi, what is the factor of safety using the maximum normal stress theory of failure?
- 5.625
- 22.5
- 4.5
- 7.5

- For a safe design in an alternating loading situation by the modified Goodman approach, two equations must be satisfied
- True
- False

- For a shaft that is transmitting 145 HP while turning at 1,200 rpm, the torque is
- 760.2 in.lb
- 6722 in.lb
- 7615.5 in.lb
- 2235.3 in.lb

- For a shaft under torque, the only type of deformation that will result is the rotation of the cross-sections with respect to each other
- True
- False

- For a brittle material, there are two curves for the stress-strain relationship–one for the tension and the other for compression.
- True
- False

- If a part fails by yielding, it will sustain permanent deformation
- True
- False

- In order to apply one of the failure theories to estimate the factor of safety, we have to
- use the state of stress
- find the principal stresses
- calculate the maximum shear stress
- find the yielding stress of the material

- Maximum shear theory of failure only applies to brittle materials
- True
- False

- Stress concentration factors are functions of
- Load
- Geometry
- Material
- Geometry and type of loading

- Stress concentration factors must be applied when we are using brittle materials
- True
- False

- The principal stresses for a part are σ_1=20 MPa, σ_2=5 MPa. What is the factor of safety using the Mises Henckey theory of failure if σ_yp=100 MPa?
- 6.1
- 6.5
- 5.55
- 8.23

- The shear stress on a cross-section of a shaft under torsion is linearly proportional to its radius
- True
- False

- A torque applied to one end of a shaft, while the other end is keyed against rotation. The torque along the shaft will be proportional to the length
- True
- False

- Ultimate stress is the same as yielding stress
- True
- False

- When solving for the factor of safety in a combined steady and alternating loading situation, stress concentration factors must be applied for both average and range stresses.
- True
- False

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