3.1u: Structural Loading & Deterioration

Question 1

1. What is a ‘Dead Load’?
   A. Load from temporary equipment
   B. Load from environmental factors like wind
   C. The constant weight of the structure itself
   D. A load caused by an impact or accident

Answer 1

C. The constant weight of the structure itself

Question 2

2. What does ‘stress’ in a material represent?
   A. Temperature increase
   B. Surface corrosion rate
   C. Internal force per unit area
   D. Number of bolts in a joint

Answer 2

C. Internal force per unit area

Question 3

3. What is the unit of stress?
   A. Newtons (N)
   B. Pascals (Pa) or N/mm²
   C. Volts (V)
   D. Kilograms (kg)

Answer 3

B. Pascals (Pa) or N/mm²

Question 4

4. What causes tensile stress?
   A. A force pushing the material together
   B. A force twisting the material
   C. A force pulling the material apart
   D. Friction from wave motion

Answer 4

C. A force pulling the material apart

Question 5

5. Which of the following is a compressive stress example?
   A. Riser pipe hanging from a deck
   B. Legs of the platform bearing weight
   C. A bent bracket
   D. A cable under tension

Answer 5

B. Legs of the platform bearing weight

Question 6

6. Bending stress occurs when:
   A. A material is twisted
   B. Equal compression and tension occur on opposite sides
   C. Only one force is applied
   D. Two parallel forces pull the same direction

Answer 6

B. Equal compression and tension occur on opposite sides

Question 7

7. Which symbol is commonly used to represent stress?
   A. α (alpha)
   B. ρ (rho)
   C. σ (sigma)
   D. Δ (delta)

Answer 7

C. σ (sigma)

Question 8

8. Fatigue fracture is caused by:
   A. High temperature
   B. Repeated cyclic loading
   C. Paint failure
   D. Over-torquing bolts

Answer 8

B. Repeated cyclic loading

Question 9

9. Brittle fracture occurs without:
   A. Warning and visible deformation
   B. Environmental influence
   C. Bolt failure
   D. Surface wear

Answer 9

A. Warning and visible deformation

Question 10

10. Which of the following can cause hydrogen embrittlement?
    A. Saltwater cooling
    B. Impressed current CP overprotection
    C. Low-pressure washing
    D. Cold water welding only

Answer 10

B. Impressed current CP overprotection

Question 11

11. What is shear stress?
    A. Force applied uniformly across a beam
    B. Compression and tension combined
    C. Sliding motion across parallel planes
    D. Force applied from explosion

Answer 11

C. Sliding motion across parallel planes

Question 12

12. Why are weld toes high-risk inspection areas?
    A. They are hard to see
    B. They are often underwater
    C. Stress concentrates there
    D. Paint won’t adhere well

Answer 12

C. Stress concentrates there

Question 13

13. What does ‘Scour’ refer to?
    A. Cracking in concrete
    B. Biological growth on steel
    C. Erosion of seabed under structures
    D. Local hardening near welds

Answer 13

C. Erosion of seabed under structures

Question 14

14. What can marine growth cause?
    A. Lower drag
    B. Weight increase and drag
    C. Improved fatigue resistance
    D. Better CP protection

Answer 14

B. Weight increase and drag

Question 15

15. Fatigue cracks most often start at:
    A. Smooth surfaces
    B. Low-stress zones
    C. Joints and welded connections
    D. Unpainted brackets

Answer 15

C. Joints and welded connections

Question 16

16. What is a neutral axis in bending?
    A. The line where compression is highest
    B. Where there is no stress during bending
    C. The axis of vibration
    D. Where the paint fails first

Answer 16

B. Where there is no stress during bending

Question 17

17. Which type of loading involves sudden impacts?
    A. Live Load
    B. Dead Load
    C. Accidental Load
    D. Hydrostatic Load

Answer 17

C. Accidental Load

Question 18

18. What is Yield Stress?
    A. Maximum point before a material breaks
    B. The point at which material returns to original shape
    C. Stress at which material begins permanent deformation
    D. The stress at maximum elasticity

Answer 18

C. Stress at which material begins permanent deformation

Question 19

19. What causes stress concentration?
    A. Smooth surfaces
    B. Uniform loading
    C. Holes, notches, or cracks
    D. Fatigue resistance

Answer 19

C. Holes, notches, or cracks

Question 20

20. Why do we inspect for thickness loss?
    A. To assess coating adhesion
    B. To determine tidal changes
    C. To evaluate material strength and safety
    D. To calibrate UT meters

Answer 20

C. To evaluate material strength and safety