What is a characteristic of thermosets?
(A)
decompose on heating
(B)
have short cure cycles
(C)
have high strain at failure
(D)
soften on heating
What is a characteristic of thermoplastics?
(A)
decompose on heating
(B)
soften on heating
(C)
have long cure cycles
(D)
are tacky
The tail fin of Airbus A310-300 is made of composites. How much was the mass of the tail fin, as compared to the metal fin, reduced by?
(A) 30000 kg
(B) 3000 kg
(C)
30 kg
(D)
300 kg
What properties may degrade by reinforcing metals with fibers?
(A) ductility and strength
(B) strength and fracture toughness
(C) ductility and toughness
(D) ductility and fracture toughness
What does PMC stand for?
(A) Polymer Matrix Composite.
(B) Polyethylene Metal Composition.
(C) Polymer Metal Composition.
What does CMC stand for?
(A) ceramic matrix compounds
(B) ceramic matrix composites
(C) ceramic metal composites
(D) ceramic material composites
What are the current service temperature limits for metals approximately?
(A) 2800°F
(B) 800°F
(C) 3700°F
(D) 1800°F
What are the current service temperature limits for ceramics?
(A) 2800°F
(B) 3700°F
(C) 1800°F
(D) 800°F
What is E-glass type fiber used for?
(A) Evaporative applications.
(B) Electrical applications.
(C) Environmental applications.
What does SMC stand for?
(A) Sheet Molding Compound.
(B) Structural Metal Composite.
(C) Strong Metal Composite.
What are the most common fibers used in advanced polymer composites?
(A) Glass, Steel, and Aluminum
(B) Glass, Steel, and Kevlar
(C) Glass, Steel, and Graphite
(D) Glass, Graphite, and Kevlar
One of the main reasons C-C composites are used in aircraft brakes is the specific heat of C-C composites. How many times that of steel is the specific heat of C-C composites?
(A) 5.0
(B) 1.0
(C) 0.5
(D) 2.5
A typical range of carbon content in carbon fiber is
(A) 93-95%.
(B) 90-95%.
(C) 93-94%.
(D) 92-95%.
Graphite fibers have one of the following carbon content
(A) 99%.
(B) 98%.
(C) more than 99%.
(D) less than 99%.
What elements are aramid fibers made up of?
(A) Carbon, Hydrogen, Oxygen and
Nitrogen
(B) Carbon, Hydrogen, Oxygen and
Graphite
(C) Carbon, Hydrogen, Nitrogen
(D) Carbon, Hydrogen, Oxygen
Thermoset plastic polymers have the following type of bonding
(A) Atomic bond.
(B) Covalent bond.
(C) Vanderwaals bond.
Which one of these is a thermoplastic?
(A) Polyesters
(B) Polyethylene
(C) Epoxy
(D) Phenolics
What are the current service temperature limits polymers can reach?
(A) 350 degrees Fahrenheit
(B) 750 degrees Fahrenheit.
(C) 450 degrees Fahrenheit.
(D) 1750 degrees Fahrenheit.
What is the main reason for reinforcing ceramics with fibers?
(A) Increase compressive strength
(B) Increase service temperature
(C) Increase fracture toughness
(D) Increase resistance to corrosion
What type of composites are most mechanical fasteners made of?
(A) Carbon-Carbon.
(B) Graphite-Epoxy.
(C) Boron-Epoxy.
What approximate range of temperatures do satellites face in space?
(A) –550°F to 200°F
(B) –550°F to 550°F
(C) –250°F to 200°F
(D) –250°F to 550°F
If I tell you that the specific gravity of steel is 7.8, what is the specific gravity of a graphite fiber approximately equal to?
(A) 7.8
(B) 1.0
(C) 2.6
(D) 1.
Which one of these is a typical example of thermoplastics?
(A) polyethylene.
(B) phenolics.
(C) polyesters.
What manufacturing method is used for short production runs of polymer matrix composite structures in the automotive industry?
(A) autoclave forming.
(B) resin transfer molding.
(C) filament winding.
Which of the following composites are replacing metals in golf club shafts?
(A) Graphite-Epoxy.
(B) Boron-Epoxy.
(C) Carbon-Carbon.
Which of the following is a drawback for phenolic resin systems?
(A) low mechanical strength.
(B) brittleness.
(C) high cost.
(D) high void content.
Which fiber reinforcement is most used for bullet proof vests?
(A) Glass.
(B) Kelvar.
(C) Boron.
(D) Graphite.
What does the D in D-glass fibers stand for?
(A) diuretic
(B) delicate
(C) dielectric
What are glass fibers are made from?
(A) slice glass.
(B) vapor deposition method.
(C) graphite
Which polymer is not desirable for smoke emission?
(A) Polyester.
(B) Polymide.
(C) Phenolic.
(D) Silicone.
Which polymer has the maximum strength?
(A) Polymide.
(B) Phenolic.
(C) Epoxy.
(D) Polyester.
For low smoke emission, which is the best polymer to use out of the polymers given below?
(A) silicone
(B) phenolic
(C) polyester
(D) epoxy
Which of these polymers has the highest service temperature?
(A) Polyester.
(B) Polymide.
(C) Phenolic.
(D) Epoxy.
Out of the polymers given below, which one has the lowest cost?
(A) polyester
(B) epoxy
(C) phenolic
(D) silicone
What does RTM stand for?
(A) resin transfer matrix
(B) resin total molding
(C) resin transfer mixing
(D) resin transfer molding
Which of these is an example of aramid fibers?
(A) Kevlar
(B) Graphite
(C) Boron
(D) Glass
Which of the polymers given below is the most desirable for low smoke emission?
(A) polyester
(B) phenolic
(C) silicone
(D) epoxy
What is one of the reasons composite materials are chosen for space applications?
(A) moisture absorption capability
(B) low specific strength
(C) dimensional stability
(D) low specific modulus
Thermosetting resins have three curing stages. At what stage does it result in irreversible hardening and insolubility?
(A) B
(B) A
(C) C
(D) D
What is the primary source of ceramic matrix composites in improving toughness?
(A) weak interfaces that blunt fiber cracks
(B) strong interfaces that continue the
matrix cracks
(C) weak interfaces that blunt matrix
cracks
(D) strong interfaces that continue the fiber
cracks