問題一覧
1
(1) When performing a ring (coin tap) test on composite structures, a change in sound may be to damage or to transition to a different internal structure. (2) The extent of separation damage in composite structures is most accurately measured by a ring(tap) test.
only No. 1 is true.
2
What chemical is applied to molds and backing plates to ensure the release of a cured part?
Mold wax
3
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate
separation of the laminates.
4
What does the acronym "TC" stand for in regard to equipment used to repair composites?
Thermo couple
5
The preferred way to make permanent repairs on composites is by
laminating on new repair plies.
6
The strength and stiffness of a properly constructed composite buildup depends primarily on
the orientation of the plies to the load direction.
7
What is the material that is used in vacuum bagging that assures separation from the part being cured
Peel ply
8
What is the material layer used within the vacuum pressure system to absorb excess resin during cure called?
Bleeder.
9
Sandwich panels made of metal honeycomb construction are used on modern aircraft because the type of construction
has a high strength to weight ratio.
10
Which degree is understood to be the warp direction of composite materials?
0
11
Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?
60:40.
12
Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying
one or more coats of suitable resin (room- temperature catalyzed) to the surface.
13
How does acoustic emission testing detect defects composite materials?
By picking up the 'noise' of any deterioration that may be present.
14
The part of a replacement honeycomb core that must line up with the adjacent original is the
ribbon direction.
15
Which of the following are generally characteristics of aramid fiber (Kevlar) composites? 1. High tensile strength. 2. Flexibility. 3. Stiffness. 4. Corrosive effect in contact with aluminum. 5. Ability to conduct electricity.
1 and 2
16
When repairing large, flat surfaces with polyester resins, warping of the surface is likely to occur. Or method of reducing the amount of warpage is to
use short strips of fiberglass in the bonded repair.
17
When balsa wood is used to replace a damaged honeycomb core, the plug should be cut so that
the grain is perpendicular to the skin.
18
What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric
Warp clock (or compass).
19
- Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water 1. Acoustic emission monitoring. 2. X-ray. 3. Backlighting.
2 and 3.
20
Composite fabric material is considered to be the strongest in what direction?
Warp.
21
One of the best ways to assure that a properly prepared batch of matrix resin has been achieved
have mixed enough for a test sample.
22
The classification for fiberglass reinforcement mat that has high resistivity and is the most common in
E-glass
23
What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?
Prime the repair with a corrosion inhibitor and seal from the atmosphere.
24
Which direction of composite fabrics are consider to be the strongest?
Warp
25
Fiberglass damage that extends completely through laminated sandwich structure
may be repaired.
26
How many of the following are benefits of using microballoons when making repairs to laminated honeycomb panels? 1. Greater concentrations of resin in edges and corners. 2. Improved strength to weight ratio. 3. Less density 4. Lower stress concentrations
2,3, and 4.
27
The classifcation for high tensile strength fiberglass used in aircraft structures is
S-glass
28
Which resin systems is typically used in composite repair and is less like to cause irritation and allergic reactions?
Epoxy
29
One method of inspecting a laminated fiberglass structure that has been subjected to damage is to
strip the damaged area of all paint and shine a strong light through the structure.
30
When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
Water only.
31
When making repairs to fiberglass, cleaning of the area to be repaired is essential for a good bond. the final cleaning should be made using
MEK (methyl ethyl ketone).
32
When repairing puncture-type damage of a metal faced laminated honeycomb panel, the edges of the doubler should be tapered to
100 times the thickness of the metal.
33
Fiberglass laminate damage not exceeding the first layer or ply can be repaired by
filling with a putty consisting of a compatible resin and clean, short glass fibers.
34
Repairing advanced composites using materials are techniques traditionally used for fiberglass repairs likely to result in
an unairworthy repair.
35
Proper pre-preg composite lay-up curing is generally accomplished by 1. applying external heat. 2. room temperature expOsure. 3. adding a catalyst or curing agent to the resin. 4. applying pressure.
1 and 4.
36
A potted compound repair on honeycomb can usually be made on damages less than
1 inch in diameter.
37
Which of the following are generally characteristk carbon/graphite fiber composites? 1. Flexibility. 2. Stiffness. 3. High compressive strength. 4. Corrosive effect in contact with aluminum. 5. Ability to conduct electricity.
2,3, and 4.
38
Which of the following, when added to wet resin provide strength for the repair of damaged fastener holes in composite panels? 1. Microballoons. 2. Flox. 3. Chopped fibers.
2 and 3.
39
The length of time that a catalyzed resin will remain a workable state is called the
pot life