M6 Flashcards
1
Q
A load that is uniformly distributed over a certain area and also the
per unit of area expressed is PSI
A
Unit stress or stress
2
Q
A kind of stress that results in the tending to stretch or lengthen the
material
A
Tensile Stress
3
Q
A force that compresses or shortens the material
A
Compressive Stress
4
Q
Materials having the nature of metal or containing metals
A
Metallic materials
5
Q
Materials containing no metal
A
Non Metallic Materials
6
Q
Iron or alloy containing iron
A
Ferrous Materials
7
Q
Metal which contain no iron
A
Non – Ferrous Materials
8
Q
A load that is uniformly distributed over a certain area and also the force per unit of area expressed is PSI
A
Unit stress or stress
9
Q
A kind of stress that results in the tending to stretch or lengthen the material
A
Tensile stress
10
Q
A force that compresses or shortens the material
A
Compressive stress
11
Q
A force that result of two metal riveted to each other which causes sliding motion or shear
A
Shearing stress
12
Q
A force that twist the material.
A
Torsion Stress
13
Q
When the stress on the area is a combination of
tensile, compressive, shearing, twisting
A
Combined stress
14
Q
When a single stress alone is considered to act
A
Simple stress
15
Q
The ratio of a lateral strain to longitudinal unit
strain for a given material
A
Poisson’s Ratio
16
Q
The maximum stress that can be applied to a
material without permanent deformation
A
Yield strength
17
Q
The stress at which a material in tension,
compression, or shear will fracture
A
Ultimate strength
18
Q
The ratio of stress to strain, within the
proportional limit of a material in tension or compression or the amount of deformation.
A
Modulus of elasticity
19
Q
Enables a material to resist penetration, wear, or cutting action
A
Hardness
20
Q
Ability of a material to withstand forces which tend to deform or the ability of a material to resist stress without breaking
A
Strength
21
Q
The selection of materials should be the best compromise between the _____________
to fulfill the requested functions and all cost at the time of aircraft development
A
Quality of the material
22
Q
Main restriction of steel is because of
A
high density >7.85 kg/dm3 (3x
the density of Al)
23
Q
Application of steel in an aircraft
A
Between 8 and 16 %(Airbus
320: 9%, Boeing 777: 11%)
24
Q
Primary advantages of high strength steels
A
High strength and high
modulus of elasticity
25
Steel composition
Iron and Carbon
26
Iron is extracted from
Iron ore > Pig iron( raw
material of steel)
27
Different kind of steels and are
distinguished by the specific properties
Steel Grades
28
Weldability is good but hardening is
unspecific and stiffness and ultimate strength is low and has carbon content of
0,05% to 0.5%
Construction steels
29
Can be hardened and is suitable for
annealing and surface hardening and has carbon content of 0.5% up to 0.8%
Carbon Steels
30
Letter used for “Structural Steel” accdg to EN 10027 standard
S
31
Letter used for “Mechanical Engineering Steels” or german word “Einsatzstahl”(case
hardening steel)
E
32
Alloy steel that is used to sustain high service loads
- Low Alloy Steels( contains
less than 5% of alloying
element and has 0.25% to
08% carbon)
- HHT(High strength steel-
Heat Treated)
- Low alloy quenching and
tempering steels
33
Ability of a material to be stretched and go back to its original state or recover
Elasticity
34
The ability of a metal to be drawn into sections without breaking and can resist deformation in tension
Ductility
35
The ability of a material that allows it to be
stretched o shaped by beating with a hammer or passing through rollers and can resist
deformation through compression
Malleability
36
The property of a material that allows it to be
deformed without breaking
Toughness
37
Ability of a metal to break when deformed or
hammered. It is the resistance to change in the relative position of molecules within the material
Brittleness
38
Ability of a material that makes it possible for
it to transmit heat or electrical conduction
Conductivity
39
Ability of a material that enables it to
withstand force over a period of time
Durability
40
Method that uses diamond tip to get the depth
Rockwell test
41
Method that uses a steel ball to get the area
Brinell test
42
Density of metal/alloy in kg/dm
Magnesium, 1.74
- Aluminum, 2.7
- Titanium, 4.5
- Iron (Ferrum), 7.85
43
Number of metals used in applications in technical fields
70 metals (chemical elements)
44
Density of heavy weight metals in kg/dm3
Between 7.85 and 9.5
45
A rigid body in which the constituent particles
are arranged in a repeating pattern.
Crystal
46
Known as the building block of a crystal
Unit cell
47
A unit cell that has a total of 9 atoms
Body-Centered-Cubic(BCC)
48
A unit cell that has a total of 14 atoms
Face-Centered-Cubic(FCC)
Examples are Cu, Au,Ni,Ag,Fe
49
A unit cell that has a total of 17 atoms.
Hexagonal-Closed-
Packed(HCP)
Examples are Co,Mg,Ti,Zn
50
Alloy steels that re corrosion resistant, has
anti chafing properties, wear resistance and
eat resistance and these are also stainless steels that is respectively high alloy steels.
- High Alloy Steels(contains
>12% chromium)
- CRES( Corrosion Resistant
Steel)
51
HHT steel that is the common steel alloy
for use in the 180-200 ksi range
4130
52
HHT steel that has a strength range of 200 ksi up to 280 ksi and commonly used in
260-280 ksi range
4340
53
HHT steel that is commonly used is
landing gear components and has 240-290 ksi range
300M
54
A process that increases the yield strength by temperature depending solution of
aluminum atoms within the iron-crystal
Precipitation Hardening(PH)
55
Small surface damage such as scratches,
nicks, or corrosion
Notch sensitivity
56
Occurs when low – alloyed steel are
deformed chipless in the cold state
Cold shortness sensitivity
57
An accidental application of heat such as
mechanical processing/ overheating during
flight
Temperature sensitivity
58
Any wetting with acidic fluids or
Mordants can lead to
Hydrogen Embrittlement
59
Applicable for steel components, which
are hardened and have to be softened for mechanical processing, also called the zero
state
Soft Annealing( becomes austenite: soft and ductile:
60
Serve for structure refinement and
releasing internal stresses in the component
Normalizing and Stress Relief
Annealing
61
Stainless steels are treated on when
in contact with lightweight alloys and the protection is for the other material not the stainless steel.
62
Used in aerospace industry because of light weight, high strength, heat resistant, corrosion resistant and has approximately 56% of the density of steal
Titanium
63
Tensile strength of pure aluminum is
Between 300 and 700 N/m2
64
When Titanium is exposed to temperature above ____ it must be protected from the atmosphere.
Contact with media which releases hydrogen is dangerous for titanium, especially when heated above ______ because this leads to____
- 450 degrees Celsius
-150 degrees Celsius
- hydrogen embrittlement
65
Heat resistance of titanium alloy when used in compressor blades
520 degrees Celsius
66
This metal is three times lighter than steel and has a melting point of 660oC
- Aluminum( Bauxite)
• one pound has more than
twice the electrical
conductivity of copper
67
Aluminum alloys that has good flowability in the liquid state
Cast Aluminum Alloys
68
Aluminum alloys that can be formed non-cutting in the cold state, which means the can be drawn, clenched, milled and forged.
Wrought aluminum alloys
69
The process of increasing the strength of aluminum alloys
Strain Hardening
70
A process that means to permanently weld metals layers onto a basis material, whilst applying high pressure.
Cladding
71
Thickness of clad layers
3-5%(sheets with thickness
that exceeds 6mm are not
cladded
72
Aluminum alloy that undergoes natural aging
2024( solidifies in 3-8 days,
after 8 hrs, 90% of strength is
achieved)
73
Aluminum alloy that undergoes artificial aging and the temp is about 120-200 degrees Celsius
7075(solidifies in 6-7 hrs)
74
Quenching interval
5-15 seconds
75
State of material after quenching
W-State
76
Carried out in aluminum alloys to bring the material into the minimum state of hardness and strength, whilst achieving the maximum stretch
Soft Annealing(zero state and
done between 400-454oC)
77
AlCuMg-alloy in a soft annealed temper which is the 0-state
2024-0
78
AlCuMg-alloy in a hardened temper, and is solution annealed, quenched, strain hardened and naturally aged
2024-T3
79
AlZnCuMg-alloy in a hardened temper, and is solution annealed, quenched, and artificially aged
7075-T6
80
A layered composite material that is a member of a family of materials called FML. An is an optimized FML for aircraft and consist of alternating layers of aluminum and glass fibre prepreg layers
- GLass Aluminum REinforced
Laminate
- Used on fuselage skin
structures on A380, aircraft
cargo bay floors and liners,
aircraft cargo explosive
resistant containers
81
Materials that consist of thin layers of metal sheet and unidirectional fibre layers embedded in an adhesive system
Fibre Metal Laminate(FML)
82
Adhesives that are best used inside the aircraft structures
Phenolic Resins
83
Resins that are best used in aircraft
external structures.
Epoxy Resins
84
A chemical reaction, generally carried out
in a presence of a catalyst, which combines small molecules(monomers), containing a double bond into a long chain molecules
Polymerization(Multiplicatio
n)
85
Monomer molecules may be:
Ethylene polymerizing to Polyethylene (PE)
Styrene polymerizing to Polystyrene (PS)
Vinyl - chloride polymerizing to Polyvinyl-chloride (PVC)
86
A chemical reaction between two similar or dissimilar basis units which have at least two functional groups
Polycondensation
87
Most famous product of polycondensation
Phenol – formaldehyde
(Bakelite)
88
Reaction of two different types of
molecules when reactive groups are
brought together
Polyaddition
89
Most famous products of polyaddition
Polyurethane and Epoxies
90
Most famous products of polyaddition
Polyurethane and Epoxies
91
Term used to describe two or more
materials that are combined to form a much stronger structure than either material itself and is used mainly to reduce weight
Composite
92
Bonding substance of composite and most
likely be liquid in form
Matrix
93
A reinforcing material in composite and
most likely be in solid form
Fabric
94
The third component of a composite
structure
Core Material
95
Made from small strands of molten silica glass and then spun together and woven into cloth but weighs more and has less
strength than other reinforcing material
Fibreglass
96
Hybrid fiberglass
Quartz – fiber
97
Fibreglass is mainly used in
Nose Radome
98
Characterized by its yellow colour,
lightweight and its excellent tensile strength
- Aramid Fibres(KEVLAR)
99
Has good mechanical properties and is very strong and stiff, which is mainly used for its rigid properties and good compressive strength but more brittle than KEVLAR
- Black Graphite/ Carbon
Fiber
• Corrosive when bonded to
aluminum
100
Style of fabric which denominates fibres which are combined to fibre bundles in large amount without any twist and nearly parallel.
Roving
101
When many rovings are laying side by side in a mat, it is called
Unidirectional tape
102
Area measured materials which are not oven and made out of or cut or non-cut, multidirectional laying fibres which are fixed by sprayed on binder
Mats
103
They are area measured materials which cross rectangularly with warp threads and filling threads.
Fabrics
104
Fibers that are already impregnated with resin in the production process and then cooled down very fast which start to cure when heat is applied.
Prepreg/ Pre-impregnated
Fibres
105
Used to connect GFRP (resin – resin
connection
Standard – Prepreg
106
Used to connect GFRP laminates with honeycombs or sheet metal parts
Bonding – Prepregs
107
Percentage of resin in and Elitrex
Prepreg Resin Content
Standard 38%
Bonding 50%
108
During the curing process in an
autoclave or in a heating press, 18-20% of resin is pressed out
Resinflux
109
Layers that build up a monolithic
wall
5 layers
110
Layers that build up a honeycomb
or sandwich
7 layers
111
A type of construction where a core
material is the center member of the assembly
Sandwich construction
112
A process which the bonding of
honeycomb is done one at a time
Corrugation process
113
A process which the bonding of
honeycomb is done with all materials bonded simultaneously
Expansion process
114
Used to bond two or more surfaces
together. Used to distribute stresses at bonding points and are moisture and corrosion resistant and eliminates the need for bolts and rivets
Adhesives
115
Known as polymerization
adhesives and used as a modifier of natural adhesives to perform better have a greater range of application
Synthetic adhesives
116
Synthetic adhesive or natural
adhesives based on Silicon
Elastomeric Adhesives
117
Transformed into tough, heat
resistant solids by the addition of catalyst or by application of heat e.g. epoxy resins
Thermosetting adhesives
118
Atmospheric pressure is used to
press two solids together so there will be no air between the two plane parallel surface
Contact adhesives
119
Contains plastic and resins
dissolved in a solvent
Solvent adhesives
120
Adhesives dissolved in water
solution
Dispersion adhesives
121
Bonding of Same Material
Cohesive
122
Bonding of different material
Adhesive
THERMOSET is irreversible
THERMOPLASTIC is reversible by application of
heat
123
Used in high-tech composites
because their mechanical properties are superior to those of polyesters
Epoxy resins(can cause
dermatitis)
124
The most important factor for
bonding, and is frequently expressed with the contact angle that is formed between a droplet of a liquid and a solid
Surface wetting
125
Takes into account that the
adhesives must penetrate into the cavities before curing to prevent bubbles
Mechanical Hooking
126
Denomination of a process to
abrade the bonding surfaces with a
chemical treatment in order to enlarge the adhesive surface
Pickling
127
A result with a contact with a sharp
object and only the surface of are affected and the edges are sharp
Scratch
128
Damage to a surface caused by
scuffing, rubbing, or scraping of the
component
Abrasion
129
When humidity penetrates a
sandwich structure this happens
Corrosion in sandwich
structures
130
Separation of materials or
laminates
Debonding
131
Separation of plies and mostly
because of resin failure
Delamination
132
Method used to detect water
absorption
NDT/ Thermograph
133
A deformity caused by extraneous
forces, which are applied to the structure
Depression or Dent
134
Repair recommended for small
damage on honeycomb materials and loses half of the material’s original strength
Filling repair
135
Consist of applying several layers
of fabric material impregnated with a resin onto the repair surface, in order to restore the damaged skin.
Wet Lay – Up
136
The amount of time you have to
work with the resins
Pot Life
137
The time which the product is still
good in an open container
Shelf Life
138
A term used if there is too much
resin applied
Resin rich
139
Defines as an undesirable, natural
reaction of materials with substances in their environments
Corrosion(derived from Latin
word corrodere which means
“gnawing away”)
140
Occurs due to the tendency of most
metals to return to their natural state by combining it with atmospheric oxygen
- Corrosion of metals
Noble Metals such as gold and platinum do not
corrode since they are chemically pure.
141
Corrosion on the surface grains of
the metal because of its crystalline structure and happens at the boundaries between grains
Intercristalline corrosion
142
Material used as coating of a metal
and used as anti-corrosion
Pure aluminum coating
(AlClad)
143
Preventive measures on corrosion
Steel requires cadmium plating, zinc
plating and aluminum coating, etc.
Aluminum alloys are usually anodized
Magnesium and magnesium alloys
requires special chemical and
electrochemical treatments and paint
finishes.
144
The corrosion process that takes
place at the surface of the electrode under the influence of electrolyte and creates a half cell
Electrochemical Reaction
145
Consist of two half cells and a
noble metal and a base metal, which serves as electrodes and are each in a sulfate solution
Galvanic cell
146
Emitting of electrons
Oxidation
147
Absorbing of electrons
Reduction
Oxidation Is Loss, Reduction Is Gain
148
Corrosion that happens without the
presence of electrolyte
Chemical corrosion
149
Electrically conductive fluid or
moisture
Electrolyte
150
A galvanic dissolution that
commonly occurs between adjacent
components, whose metals have different electrochemical potential and under the influence of electrolyte
Electrochemical Corrosion
151
Also called the Microbes corrosion
and is caused y a direct chemical attack of metabolic products of microorganisms
Biological corrosion
152
When mechanical forces act on a
component which leads to corrosion
Stress corrosion
153
Used as protection on titanium
Chromium acid anodize
154
Used as lubricant for fastener
- Cetylalkohol
Most cathodic is Carbon
Most anodic is Magnesium
155
Occurs when two dissimilar metals
make electrical contact in the presence of an electrolyte
Galvanic Corrosion
156
The most common type of
corrosion on aluminum and magnesium and appears a white powdery deposit and the starting point for intergranular corrosion
Pitting Corrosion
157
A corrosion on the grain
boundaries of the metal and occurs when cladding is damaged
Intergranular Corrosion
158
Mostly seen on extruded sections,
this advanced type of intergranular
corrosion exhibits itself by lifting up the surface of a metal by force
Exfoliation Corrosion
159
Results in the rubbing movement
between two heavily loaded surfaces and can eventually cause cracking fatigue
Fretting Corrosion
160
A corrosion cause by bacteria,
fungi or yeast in an unclean fuel and looks like a sludge like deposit.
Microbial Corrosion
161
Necessary if a contamination of
fuel tank is detected
Biocide (kathon or biobor)
162
Occurs between two materials that
come into contact, metallic or non-metallic
- Crevice Corrosion
Solid rivets are Self-sealing fasteners
For shearing loads in fasteners small
head is used for weight saving
163
Thread formed on a cylinder is
known as
Straight or Parallel Thread
164
If groove is formed on the external
Male thread
165
If groove is formed internal
Female Thread
166
Thread formed and cut onto a
conical part
Taper thread
167
Shape of one complete contour
Form
168
Prominent point of the thread
Crest
169
Bottom point of the thread groove
Root
170
Slope of the thread between the
root and crest
Flank
171
A screw that has a deeper thread
and have fewer threads
Coarse Pitch
172
A screw that have a stronger root
portion, tighter grip and more resistant to shaking loose
Fine Pitch
173
Most common thread form and
shaped to combine strength with ease of
engagement
- Vee Thread Install bolts and screws foremost and uppermost
174
It is where the code marking of
aircraft bolts are identified
- Bolt head
NE = Long Thread
NF= Short Thread
175
A piece of rod, threaded at each
end with a plain portion in the middle
Stud
176
A piece of a hexagonal metal bar,
drilled and tapped through its axial center –
line
Stud box
177
Used extensively to secure thin –
gauge sheet metal parts where nuts and bolts are either impractical or too expensive
Self-Tapping Screws
178
is used when a slight range of
movement is necessary to ensure the bolt can locate
Anchor Nuts
179
Permit each thread to adjust to the
screw and assure full load distribution throughout the entire length of the thread
Heli – Coil Inserts
180
A process of securing all aircraft
bolts, nuts, screws, pins and other fasteners so that they do not work loose due to vibration
Safetying
181
Most common method of wire
locking
Double - Twist Method
182
Most positive and satisfactory
method of safetying and is a method of wiring together two or more units in such a manner that any tendency of one to loosen is counteracted by the tightening of the wire
Wirelocking
183
used to secure bolts, screws, nuts
and pins
Cotter Pins
184
Given to a specially – shaped piece
of metal that is used to transmit at
considerable mechanical power from a shaft to hub
Keys
185
Deformed portion of the Rivet
- Upset Head
Rivet diameter is at least 3 times the thickness of the thickest sheet being joined
186
a process which a rivet material
have to be heat treated before using them in the manufacturing process
- Solution Annealing(Annealed at 495deg celcius and
quenched at 20 deg celcius)
At -18deg celcius
temperature rivets can be stored for up to 7 days
At -20 deg celcius
temperature rivets can be stored for up to
20 days
187
the time between opening the
furnace or removing the rivets from the salt bath and the complete immersion of the load into the quenching medium
Quench Delay
188
The time, within which the rivets
must be upset, at room temp. 25 degrees Celsius
Maximum Handling Time
189
A tapered bolt with a threaded end
and a self – locking nut and used in areas where a high fatigue performance is required
Taper – Lok
190
A combination of a rivet and a nut,
resembling a hollow rivet with threads inside its shank
Rivnut
191
Combined thickness of the material
to be joined
Grip Length
