C6 Failure Flashcards
1
Q
type of failure
2 types
A
- ductile
- brittle
2
Q
elobrate
ductile
A
- occur at high temp
- show plastic deform
- has 5 cup-cone fracture stage
3
Q
elobrate
brittle
A
- occur at low temp
- not showing any deform
- break without warning
- when look at microscope can see thin line sample fail
4
Q
what are
stages in cup-and-cone fracture
A
- necking
- cavity formation
- coalescence cavities form crack
- crack propagation
- fracture
5
Q
the sharp tip in sample crack can causing
A
it propogate crack
6
Q
how to stop crack growth
A
blunt the tip
7
Q
crack growth condition
A
K ≥ Kc = Yθ√(πa)
Y=material behaviour, a=area
8
Q
Formula for: θ (y-axis) vs a max (x-axis)
A
θ design < Kc / Y(√πa max)
9
Q
Formula for graph: a max (y-axis) vs θ (x-axis)
A
a max < (1/π) [Kc / Y(θ design)]^2
10
Q
for both graph: (a max vs θ) & (θ vs a max)
the area under graph means
A
no fracture
11
Q
for both graph: (a max vs θ) &
the area above graph means
A
fracture
12
Q
ductile brittle transition test
A
charpy experiment test
13
Q
charpy experiment test conduct at diff temp
A
- to the left (low temp): brittle
- to the right (high temp): ductile
- impact energy = (max - min) / 2
14
Q
Type application of failure
A
- Fatigue
- Creep
15
Q
what is fatigue
A
- predict max cycle
- repeated cycling load
