Composite Structures And Transparent Plastic Materials
Airflame
- 1.Metal fasteners used with carbon/graphite composite structures
- A.
Must be constructed of high strength aluminum-lithium alloy
- B.
Must be constructed of material such as titanium or corrosion resistant steel
- C.
May be constructed of any of the metals commonly used in aircraft fasteners.
- 2.Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the
- A.
Possibility of causing delamination
- B.
Difficulty in forming a proper shop head.
- C.
Increased possibility of fretting corrosion in the fastener
- 3.Sandwich panels made of metal honeycomb construction are used on modern aircraft because this type of construction
- A.
May be repaired by gluing replacement skin to the inner core material with thermoplastic resin
- B.
Has a high strength to weight ratio.
- C.
Is lighter than single sheet skin of the same strength and is more corrosion resistant
- 4.(1) When performing a ring (coin tap) test on composite structures, a change in sound may be due 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 (coin tap) test.
- A.
Only No.1 is true
- B.
Only No.2 is true
- C.
Both No.1 and No.2 are true
- 5.Which of these methods may be used to inspect fiberglass/ honeycomb structures for entrapped water?1. Acoustic emission monitoring2. X-ray3. Backlighting
- A.
1 and 2
- B.
2 and 3
- C.
1 and 3
- 6.One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to
- A.
Perform a chemical composition analysis
- B.
Have mixed enough for a test sample
- C.
Test the viscosity of the resin immediately after mixing
- 7.Composite inspections conducted by means of acoustic emission monitoring
- A.
Pick up the "noise" of corrosion or other deterioration occurring
- B.
Create sonogram pictures of the areas being inspected
- C.
Analyze ultrasonic signals transmitted into the parts being inspected
- 8.What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?
- A.
Prime the repair with a corrosion inhibitor and seal from the atmosphere
- B.
Paint the outside area with several coats of exterior paint
- C.
None. Honeycomb is usually made from a man made or fibrous material which is not susceptible to corrosion.
- 9.One method of inspecting a laminated fiberglass structure that has been subjected to damage is to
- A.
Strip the damaged area of all paint and shine a strong light through the structure
- B.
Use an eddy current probe on both sides of the damaged area
- C.
Use dye penetrant inspection procedures, exposing the entire damaged area to the penetrant solution.
- 10.How many of the following are benefits of using microballons when making repairs to laminated honeycomb panels?
- Greater concentrations of resin in edges and corners.
- Improved strength to weight ratio.
- Less density.
- Lower stress concentrations.
- A.
2, 3, and 4
- B.
1, 2, and 4
- C.
1, 3, and 4
- 11.The length of time that a catalyzed resin will remain in a workable state is called the
- A.
Pot life
- B.
Service life
- C.
Shelf life
- 12.A category of plastic material that is capable of softening or flowing when reheated is described as a
- A.
Thermoset
- B.
Thermoplastic
- C.
Thermocure
- 13.The classification for high tensile strength fiberglass used in aircraft structures is
- A.
S
- B.
G
- C.
E
- 14.Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying
- A.
A piece of resin impregnated glass fabric facing.
- B.
One or more coats of suitable resin (room temperature catalyzed) to the surface.
- C.
A sheet of polyethylene over the abraded surface and one or more coats of resin cured with infrared heat lamps
- 15.The classification for fiberglass reinforcement material that has high resistivity and is the most common is
- A.
E
- B.
G
- C.
S
- 16.A potted compound repair on honeycomb can usually be made on damages less than
- A.
2 inches in diameter
- B.
1 inches in diameter
- C.
4 inches in diameter
- 17.Composite fabric material is considered to be the strongest in what direction?
- A.
Fill
- B.
Bias
- C.
Warp
- 18.The strength and stiffness of a properly constructed composite buildup depends primarily on
- A.
The orientation of the plies to the load direction.
- B.
The ability of the fibers to transfer stress to the matrix
- C.
A 60 percent matrix to 40 percent fiber ratio
- 19.Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?
- A.
60:40
- B.
40:60
- C.
50:50
- 20.What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?
- A.
Release
- B.
Bleeder
- C.
Breather
- 21.Proper pre-preg composite lay-up curing is generally accomplished by
- applying external heat
- room temperature exposure
- adding a catalyst or curing agent to the resin
- applying pressure
- A.
1 and 4
- B.
2 and 3
- C.
1, 3, and 4
- 22.When repairing large, flat surfaces with polyester resins, warping of the surface is likely to occur. One method of reducing the amount of warpage is to
- A.
Use less catalyst than normal so the repair will be more flexible.
- B.
Add an extra amount of catalyst to the resin
- C.
Use short strips of fiberglass in the bonded repair
- 23.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
- A.
MEK (methyl ethyl ketone)
- B.
A thixotropic agent.
- C.
Soap, water, and a scrub brush
- 24.When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
- A.
Water only
- B.
Water displacing oil
- C.
Water soluble oil
- 25.Fiberglass laminate damage not exceeding the first layer or ply can be repaired by
- A.
Sanding the damaged area until aerodynamic smoothness is obtained
- B.
Trimming the rough edges and sealing with paint
- C.
Filling with a putty consisting of a compatible resin and clean, short glass fibers
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