Quiz 1

Question 1

True or False: Failure only occurs when a component breaks.

Answer 1

False. Failure occurs whenever the component is unable to function nominally.

Question 2

What is failure?

Answer 2

Inability of a component to function as intended.

Question 3

Why is the study of failure important?

Answer 3

Helps to learn from mistakes to prevent future failures and for mitigation.

Question 4

What is the main cause of failure in aircraft components?

Answer 4

Fatigue

Question 5

What is the main cause of failure in the general engineering industry?

Answer 5

Corrosion

Question 6

What are the four main categories/modes of failure?

Answer 6

Deformation, fracture, wear, and corrosion

Question 7

What is deformation?

Answer 7

Any change to the shape of the material

Question 8

What is fracture?

Answer 8

Any cracks or breaks due to stress

Question 9

What is corrosion?

Answer 9

Deformation due to the material due to chemical reactions with the environment

Question 10

What is wear?

Answer 10

Undesired removal of material from contacting surfaces by mechanical action (i.e. gears)

Question 11

Define failure mode

Answer 11

Specific manner in which a failure occurs as a result of the failure mechanism

Question 12

What are the primary causes of equipment failure?

Answer 12

Design deficiencies, material defects, manufacturing/installation defects, and service life anomalies

Question 13

What does root cause analysis refer to?

Answer 13

Understanding of the underlying cause of failure so corrective action can be taken

Question 14

What are the energy forms?

Answer 14

Chemical, Optical, Mechanical, Electrical, Thermal, Magnetic, Acoustic, and Nuclear (COMET MAN)

Question 15

Which has the larger depth of field, SEM or OM?

Answer 15

SEM

Question 15

Which microscope (SEM, TEM, or OM) has the highest resolution?

Answer 15

TEM; resolution up to 2 Angstrom

Question 15

What do SEM, TEM, and OM stand for?

Answer 15

Scanning Electron Microscopy, Transmission Electron Microscopy, and Optical Microscope

Question 16

Which microscope (SEM, TEM, or OM) has the highest magnification?

Answer 16

TEM; goes up to 1,000,000x magnification

Question 17

Which technique (SEM, TEM, or OM) is most useful for fractography?

Answer 17

SEM

Question 17

What is fractography?

Answer 17

Study of the fracture surface of a material

Question 18

Which microscope (SEM, TEM, or OM) requires the easiest sample preparation?

Answer 18

SEM

Question 19

How would you prepare an OM sample?

Answer 19

Sectioning, Mounting, Grinding, Polishing, Etching

Question 20

Which microscope (SEM, TEM, or OM) has the most difficult sample preparation?

Answer 20

TEM

Question 21

Which tests can be performed to determine the mechanical properties of a sample?

Answer 21

Mechanical (compression and tension) and hardness tests

Question 22

Which tests can be performed to determine the chemical composition of metals?

Answer 22

Energy Dispersive Xray (EDX) using SEM and spectroscopy

Question 23

Which tests can be used to classify polymeric materials?

Answer 23

Fourier Transform Infrared spectroscopy (FTIR)

Question 24

Which tests might be helpful in determining manufacturing imperfections?

Answer 24

X-ray CT, ultrasonic C-scan, and SEM

Question 25

What are the steps in failure analysis?

Answer 25

0: Think 1: Collect Data 2: Preserve Fracture Surface 3: Preliminary Visual Exam 4: Non-Destructive Testing (NDT) 5: Chemical Analysis 6: Mechanical Testing 7: Macroscopic Exam 8: Microscopic Exam 9: Metallography 10: Failure Mechanisms 11: Calculations/FEA 12: Test in Service Conditions 13: Reporting

Question 26

True or False: The order of the failure analysis steps are not very important as long as all the steps are completed.

Answer 26

False

Question 27

Why do structures fail?

Answer 27

Negligence during design, construction, or operation and new application of the design

Question 28

What is failure analysis?

Answer 28

The systematic process of investigating and understanding the reasons behind the failure of a component, system, or material

Question 29

What is failure prevention?

Answer 29

Involves strategies and practices designed to avoid or minimize the occurrence of failures in systems, components, or materials

Question 30

What are types of distortion?

Answer 30

Yielding during service, creep, and buckling

Question 31

What is the most common type of corrosion?

Answer 31

Uniform corrosion due to rust on iron or steel

Question 32

What are types of fracture?

Answer 32

Monotonic and fatigue

Question 33

What is included in a case study?

Answer 33

Summary of events, documentation and analysis, discussion of ramifications, and recommendations

Question 34

What should be considered during failure analysis?

Answer 34

Physical evidence, use of engineering and scientific principles, and analytical tools

Question 35

What are the categories of root cause analysis?

Answer 35

Physical Roots (i.e. equipment), Human Roots (i.e. human factors), and Latent Roots (i.e. procedural/systemic cause)

Question 36

What is a physical root?

Answer 36

Technical explanation of why a part failed

Question 37

What is a human root?

Answer 37

Human errors that led to the physical cause -- whether acts of omission or commission

Question 38

What is a latent root?

Answer 38

Deficiency in management procedures or systems that allowed human errors to go unchecked

Question 39

What is metallography?

Answer 39

The study of structure and composition of metals using microscopy

Question 40

What is a microstructure?

Answer 40

Arrangement of phases and defects within a material

Question 41

What is a crystal structure?

Answer 41

Arrangement of atoms within a unit cell

Question 42

What are types of non-destructive testing?

Answer 42

X-ray (radiography), ultrasound, dye penetrant, magnetic particle inspection (MPI), and studying cracks and porosity