Loading and Deterioration Questions Flashcards
What is correct way of mathematically calculating stress?
Stress = force / area
When the atoms in a material are pulled apart, this is known as what stress?
Tensile
What type of stress is a combination of 2 other types of stress?
Bending stress
The yield stress is sometimes called ?
Elastic limit
Fatigue failure is most likely going to be what type of fracture?
A fracture with no deformation (brittle)
Fatigue failure in offshore structures is typically associated with a fracture with no deformation (brittle). This is because fatigue failures are often the result of cyclic stresses that cause cracks to initiate and propagate in a material until a critical crack length is reached, leading to sudden fracture without significant plastic deformation12. Therefore, the most likely type of fracture due to fatigue failure in an offshore structure would be:
c. A fracture with no deformation (brittle)
The UTS for a given material is:
The maximum a material can be loaded before failure
Which of the following are stress concentration points?
Note: Answer is D - All of the above
a.Cracks
b. Notches
c. Sharp corners
d. All of the above
The steady force exerted by a fluid as it passes a stationary structure is known as the?
Drag force
Segregation bands/lines occur:
Answer: In the centre of the plate and are low melting point impurities such as sulphur and phosphorous
a. During rolling when overlapping material does not fuse to base material
b. When a pipe in not of a correct tensile strength
c. In the centre of the plate and are low melting point impurities such as sulphur and phosphorous
d. When the plate has been exposed to extreme weather conditions
Imagine you have a bag of mixed candies—some are chocolate, some are caramel, and some are mint. When you pour them out, most of the time, they mix up randomly. But sometimes, you might find a little clump of just chocolate or just caramel candies together. That’s a bit like what happens with metals when they cool down from being really hot.
Metals are made up of different kinds of tiny parts, like our candies. When metal cools down, these tiny parts sometimes don’t mix evenly. So, just like finding a clump of chocolate candies, you might find a spot in the metal where there’s more of one kind of tiny part, like sulphur or phosphorous. These parts melt at a lower temperature than the rest of the metal, so they can make lines or bands where they’ve clumped together.
This doesn’t mean the metal is bad, it’s just how it cooled down. It’s important for people who use metals to know about these spots, so they can make sure the metal is good for building things like bikes, cars, or bridges
The most suitable weld cap profile for reducing high stress concentration areas would be:
Concave fillet
Movements of material of the seabed can affect the foundations of a structure. What is this called?
Scour
Fatigue is the local failure of the material by crack growth caused by:
Cyclic loading
In which area of the weld would you generally find hydrogen induced cold cracking (HICC)?
Heat affected zone (HAZ)
Which of the following could lead to residual stresses in the structure?
Note: d. All of the above
a. Welding
b. Force fitting members of the structure together
c. Incorrect heat treatment
d. All of the above
When designing a structure for static loading it is generally designed using:
100 year storm wave
