Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mod 6 > 6.3.1 > Flashcards

6.3.1 Flashcards

1
Q

What is nomex (reinforcing material) used in?

A

Flame resistant clothing and radiation resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is fibreglass made from?

A

Small strands of molten silica glass that are spun together to create a cloth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the benefit of E-glass?

A

Highly resistant to electricity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the benefit of S-glass?

A

Very high tensile strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What colour is Kevlar and aramid fibres?

A

Yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How would aramid fibres be repaired?

A

With fibreglass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the main disadvantage of Kevlar?

A

It is sensitive to the environment (moisture and sunlight)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is used to stop the corrosion between carbon fibre and aluminium?

A

A layer of fibreglass to isolate them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What direction force is Kevlar stronger in?

A

Tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What direction of force is graphite/ carbon fibre stronger in?

A

Compressive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the warp in fabric orientation?

A

The length of the fabric as it comes off the roll

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the weft/fill of fabric orientation?

A

It runs perpendicular to the warp fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the salvage edge in fabric orientation?

A

It runs parallel to the warp to prevent the edges unraveling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the bias in fabric orientation?

A

It runs 45° to warp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What direction can fabric be stretched in?

A

In the bias but not along the warp or weft/fill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is meant by unidirectional fibres in relation to fabric orientation?

A

major fibres which run in direction of the warp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is meant by bi-directional fibre in relation to fabric orientation?

A

When fibres run in multiple different directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are mats in relation to fabric orientation?

A

They consist of chopped fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are fabric weaves?

A

The different varieties of fibre cross hatching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the two parts to a resin?

A

A resin and a hardener (catalyst)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the two categories of resins?

A

Thermoplastics and thermosets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is special about a thermoplastic resin?

A

It can constantly change its shape when heated is added

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What temperature must thermoplastic resin not exceed unless you’re changing its shape?

A

750°F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name an example of a thermoplastic?

A

Plexiglass/acrylic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is special about thermoset resin?

A

Once heated and set it cannot be changed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are most composite structures bonded with?

A

Thermoset resins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Name an example of a thermoset resin?

A

Bakelite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What type of resin are epoxy resins?

A

Thermoset resin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where are epoxy resins mostly used?

A

When bonding metal to composite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is prepeg an abbreviation of?

A

Pre-impregnated fabrics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is prepreg?

A

Fabrics that already have resin impregnated in them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Why does prepreg need to be stored in a freezer?

A

To prevent the resin curing at room temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is a sandwich construction?

A

When a core material is bonded between two thin face sheets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the two types of honeycomb fabrication?

A

Corrugation process and the expansion process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the main advantage of honeycomb materials?

A

Very high strength to weight ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is honeycomb ribbon direction?

A

The direction in which the length of strips make up the core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What happens if you pull honeycomb perpendicular to the ribbon direction?

A

It will separate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What happens if you pull honeycomb parallel to the ribbon direction?

A

It is impossible to separate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the four ways to disperse electrical charge on composite components?

A
  • flame spray
  • bonding leads
  • aluminium wires woven in
  • thin aluminium foil bonded in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What must be used when working on composite materials?

A

Material safety data sheets (MSDS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is an adhesive?

A

It’s a substance used to bond two or more surfaces together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How does surface tension affect adhesion?

A

It determines how far the adhesive penetrates the tiny depressions in the surface

43
Q

What happens to thermosetting adhesives when a catalyst or heat is added?

A

It will set into a hard solid adhesive

44
Q

What happens when heat is reapplied to a thermoplastic resin?

A

It will go back to a soft resin to be applied again

45
Q

What is special about solvent adhesives?

A

The solvent has to evaporate to cure the adhesive

46
Q

What is a dispersion adhesive?

A

An adhesive that dissolves in a water solution

47
Q

What is a resin adhesive?

A

An adhesive that can only cure by a chemical reaction

48
Q

What is film adhesives?

A

A material that has adhesive on both side already

49
Q

What temperature must film adhesives be stored at?

A

-18C

50
Q

What is foaming adhesive film?

A

An adhesive sheet that expands during curing to fill gaps

51
Q

What is a thixotropic agent?

A

It is an agent used to thicken a liquid

52
Q

How should resins be mixed?

A

In a wax free container by adding the accelerator to the resin base

53
Q

How long should the mixing process of resins take?

A

3 to 5 minutes

54
Q

If a resin base has been stored in a freezer what should you do?

A

Allow to reach ambient temperature before weighing and mixing

55
Q

What happens if you add too much catalyst to resin?

A

Decreases in strength of mix and could combust

56
Q

Why cant you store pre mixed resin?

A

Because the catalyst massively reduces the shelf life

57
Q

Why and Where are epoxy resins used?

A

External components due to good metal adhesion

58
Q

Why and Where are phenolic resins used?

A

Cabin furnishing due to their low toxicity in a fire

59
Q

Why and where are polyester resins used?

A

Used with glass fibre to for a strong durable material

60
Q

Why and where are vinyl Ester resins used?

A

Repairing fuel tanks due to high corrosion resistance

61
Q

Why must you never add catalyst and accelerator together?

A

It will create a large exothermic reaction resulting in fire and explosions

62
Q

Why is it important to get the correct ratio of resin and hardener?

A

if the ratio is wrong then unreacted resin/hardener will be left in the cured resin

63
Q

If you cant find the correct mixing ratio who should you contact?

A

The manufacturer

64
Q

How do you speed up a cure for room temperature resins?

A

Increase the atmospheric temperature

65
Q

Why is it important to remember epoxy rein cure by linking molecules together?

A

Because the exact amount of molecules must be present to get the best cured resin

66
Q

What does phr mean in relation to resin ratios?

A

Parts per hundred resin

67
Q

What is mechanical hooking?

A

When adhesive must penetrate into cavities before curing, otherwise trapped air will reduce the strength of adhesion

68
Q

What is the phenomenon of surface wetting?

A

The contact angle that is formed between droplet of liquid and a solid

69
Q

What is used to investigate the damage to a composite material?

A

The structural repair manual

70
Q

How do you tell if damage is acceptable?

A

Using the structural repair manual

71
Q

What are the two main categories of damage to a composite material?

A

Skin perforated or skin not perforated

72
Q

What is delamintaion of a composite material?

A

When the reinforcing material layers separate from the matrix

73
Q

What is BVID?

A

Barely visible impact damage

74
Q

What is deboning in composites?

A

When the skin stops adhering to the core material

75
Q

What is used to determine the amount of barely visible impact damage?

A

Close visual inspections and NDT

76
Q

What is the definition of a scratch?

A

Contact with a sharp object and only surface fibres are affected

77
Q

What is a gouge?

A

Wider and deeper than a scratch, several plies are affected

78
Q

How would you repair a gouge?

A

Remove damaged plies then performing a hand lay up

79
Q

What is classified as abrasion damage?

A

Small damage to the surface protection by scuffing or scraping

80
Q

How and why is abrasion repaired?

A

Restoring the protective surface to prevent fluid ingress

81
Q

What happens to a non conductive material if it is hit by lightning?

A

It will be blown out and the core will be vaporised

82
Q

What happens to a conductive material if it is hit by lightning?

A

Small damage to the material will be found

83
Q

Where is erosion most likely to take place?

A

Leading edge surfaces

84
Q

During a repair why is it important to ensure it is completely dry?

A

Heating of the liquid could cause delamination

85
Q

What must be done if a dent is found?

A

NDT

86
Q

When tap testing honeycomb what must you do?

A

Tap test both sides of the honeycomb

87
Q

What are the three types of repairs?

A
  • Temporary repair
  • permanent cosmetic repair
  • permanent structural repair
88
Q

Where are repair instructions found?

A

Structural repair manual

89
Q

How is surface protection removed ready for repair?

A

Mechanical methods only

90
Q

Why cant chemical strippers be used to remove surface protection?

A

It may cause deterioration of the resin

91
Q

What is the name of the technique used to remove composite materials?

A

Scarfing

92
Q

If damage reaches the core material of a composite what must you do?

A

The damaged core should be routed out carefully and replaced with a similar material

93
Q

If you’re repairing honeycomb with more honeycomb what must you ensure?

A

That the honeycomb is joined in the same ribbon direction

94
Q

What should you not do when cleaning a repair surface?

A

Apply cleaning agent directly on the repair surface

95
Q

What is meant by pot life?

A

How long the resin is usable once mixed

96
Q

What is meant by shelf life?

A

How long a resin can sit in storage in an unopened container

97
Q

What is meant by resin rich?

A

Too much resin is used

98
Q

What happens to the composite if it is resin rich?

A

Makes it brittle and heavy

99
Q

What is meant by resin starved?

A

There is too little resin

100
Q

What is the result if a composite is resin starved?

A

It wont be able to correctly transfer stresses to the fibres

101
Q

When mixing resin into a fabric what must you take care with?

A

To not distort the weave of fabric

102
Q

What are the two types of wet lay up?

A

Pre-peg and wet application

103
Q

What material is used for vacuum bagging?

A

Nylon

Mod 6 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions