Sheet Metal and Non-Metallic Structures Flashcards
A well-designed rivet joint will subject the rivets to what?
shear loads.
A main difference between Lockbolt/Huckbolt tension and shear fasteners (other than their application) is the what?
number of locking collar grooves.
Alloy 2117 rivets are heat treated how?
by the manufacturer and do not require heat treatment before being driven.
The general rule for finding the proper rivet diameter is what?
three times the thickness of the thickest sheet.
The shop head of a rivet should be what?
one and one-half times the diameter of the rivet shank.
One of the main advantages of HI-LOK type fasteners over earlier generations is that what?
they can be installed with ordinary hand tools.
Which of the following is one advantage of HI-LOK fasteners?
Inability to be over-torqued.
The markings on the head of a Dzus fastener identify the what?
body diameter, type of head, and length of the fastener.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in what?
hundredths of an inch.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in what?
sixteenths of an inch.
Threaded rivets (rivnuts) are commonly used to what?
attach parts or components with screws to sheet metal.
The installation of CherryMAX and Olympic-Lok rivets is accomplished by utilizing what?
a pulling tool.
Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the what?
possibility of causing delamination.
Metal fasteners used with carbon/graphite composite structures…
must be constructed of material such as titanium or corrosion resistant steel.
Sandwich panels made of honeycomb construction are used on aircraft because this type of construction…
saves weight while not comprising strength.
Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water?
X-ray and backlighting.
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.
When repairing puncture-type damage to a metal-faced laminated honeycomb panel, the edges of the doubler should be tapered to…
100 times the thickness of the metal.
One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to what?
have mixed enough for a test sample.
How does acoustic emission testing detect defects in composite materials?
By picking up the “noise” of any deterioration that may be present.
When conducting a tap test on a composite panel, which of the following sounds would indicate delamination?
Dull thud.
What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?
Paint the repair with a corrosion inhibitor and seal from the atmosphere.
One method of inspecting a laminated fiberglass structure that has been subjected to damage is to what?
strip the damaged area of all paint and shine a strong light through the structure.
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate what?
separation of the laminates.
Which of the following are benefits of using microballoons when making repairs to laminated honeycomb panels?
Improved strength-to-weight ratio, less density, and lower stress concentrations.
The length of time that a catalyzed resin will remain in a workable state is called the what?
pot life.
A category of plastic material that is capable of softening or flowing when reheated is described as a what?
thermoplastic
The classification of high tensile strength fiber-glass used in aircraft structures is what?
S-glass.
Which is an identifying characteristic of acrylic plastics?
Zinc chloride will have no effect.
Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying what?
One or more coats of suitable resin (room-temperature catalyzed) to the surface.
The classification for fiberglass reinforcement material that has high resistivity and is the most common is what?
E-glass.
A potted compound repair on honeycomb can usually be made on damages less than what?
1 inch in diameter.
Composite fabric material is considered to be the strongest in what direction?
Warp.
What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?
Warp clock (or compass)
The strength and stiffness of a properly constructed composite buildup depends primarily on what?
the orientation of the plies to the load direction.
Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?
60:40
What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?
Bleeder.
Proper prepeg (preimpregnated materials) composite lay-up curing is generally accomplished by what?
applying external heat and pressure.
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 what?
use short strips of fiberglass in the bonded repair.
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 what?
MEK (methyl ethyl ketone)
When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
Water only.
Fiberglass laminate damage not exceeding the first layer or ply can be repaired by what?
filling with a putty consisting of a compatible resin and clean, short glass fibers.
Fiberglass damage that extends completely through a laminated sandwich structure…
may be repaired.
Fiberglass laminate damage that extends completely through one facing and into the core…
requires the replacement of the damaged core and facing.
Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in what?
an unairworthy repair.
The preferred way to make permenant repairs on composites is by what?
laminating on new repair plies.
Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels?
Flox and chopped fibers.
The part of a replacement honeycomb core that must line up with the adjacent original is the what?
ribbon direction.
Which of the following are generally characteristic of aramid fiber (Kevlar) composites?
High tensile strength and flexibility.
Which of the following are generally characteristic of carbon/graphite fiber composites?
Stiffness, high compressive strength, and corrosive effect in contact with aluminum.
If an aircraft’s transparent plastic enclosure exhibit fine cracks which may extend in a network over or under the surface or through the plastic, the plastic is said to be what?
crazing, baby.
When installing transparent plastic enclosures which are retained by bolts extending through the plastic material and self-locking nuts, the nuts should be what?
tightened to a firm fit, then backed off one full turn.
If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document?
TSO C22.
Which is considered good practice concerning the installation of acrylic plastics?
When rivets are used, adequate spacer or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.
The coefficient of expansion of most plastic enclosure materials is what?
greater than both steel and aluminum.
If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be what?
covered with a thin coat of wax.