IET 365 Final Exam questions with
complete solutions
Reinforcement Diagram - correct answer ✔✔
Advanced Composite - correct answer ✔✔ A fibrous material embedded in a resin matrix. Has
superior strength and stiffness.
Composite Materials - correct answer ✔✔ Two or more substances which are combined to
produce material properties not present when either substance is used alone. Each substance
still retains its molecular structure.
Resin/Matrix (Thermoset) - correct answer ✔✔ The material that bonds the fibers together and
distributes the stress to the fibers.
Common type of Resin/Matrix - correct answer ✔✔ 1. Epoxy
2. Polyester
3. Vinyl-ester
4. Urethane
Four Functions of Resin/Matrix - correct answer ✔✔ 1. Transfer stress from fiber to fiber
2. maintain fiber orientation
3. prevent fibers from abrading each other
4. gives environmental resistance (protects)
,Reinforcements - correct answer ✔✔ Material used to strengthen the resin/matrix; at least 50
times stronger and 25-150 times more rigid than the resin/matrix
Main Advantages of Composite Materials - correct answer ✔✔ 1. Increase stiffness, strength, or
dimensional stability
2. Reduce cost
3. Reduce weight
4. Improve design flexibility
Advantages of Composite Materials - correct answer ✔✔ 1. Increase toughness
2. Increase heat-deflection temperature
3. Increase mechanical and sound damping
4. Reduce permeability to gases and liquids
5. Modify electrical properties
6. Decrease water absorption
7. Decrease thermal expansion
8. Increase chemical wear and corrosion resistance
9. Maintain strength/stiffness at high temps. while under strain conditions in corrosive
environments
10. Increase secondary uses and recyclability and reduce negative impact on the environment
Main Disadvantages of Composite Materials - correct answer ✔✔ 1. Labor Intensive
2. Lack of train personnel
3. Inconsistent processing/fabrication
Disadvantages of Composite Materials - correct answer ✔✔ 1. Toxic
2. Required processing
, 3. High tooling cost
4. High cost of equipment
5. Lack of data
6. Underdeveloped inspection techniques
Common types of reinforcement fibers - correct answer ✔✔ 1. Fiberglass
2. Aramid (Kevlar)
3. Carbon/Graphite
4. Boron
Fiberglass Characteristics - correct answer ✔✔ Color: White, Silver, Gray, Translucent
Years: 1940-50's
How is Fiberglass produced? - correct answer ✔✔ Made from small strands of molten glass,
which are then spun together and woven into cloth
Advantages of Fiberglass - correct answer ✔✔ 1. Low cost compared to other types of fibers
2. Availability
3. Good tensile strength
4. Good shear strength
Disadvantages of Fiberglass - correct answer ✔✔ 1. Lower impact strength than other fibers
2. Heavier than other types of fibers
Different Types of Fiberglass - correct answer ✔✔ 1. E-Glass
2. S-Glass
complete solutions
Reinforcement Diagram - correct answer ✔✔
Advanced Composite - correct answer ✔✔ A fibrous material embedded in a resin matrix. Has
superior strength and stiffness.
Composite Materials - correct answer ✔✔ Two or more substances which are combined to
produce material properties not present when either substance is used alone. Each substance
still retains its molecular structure.
Resin/Matrix (Thermoset) - correct answer ✔✔ The material that bonds the fibers together and
distributes the stress to the fibers.
Common type of Resin/Matrix - correct answer ✔✔ 1. Epoxy
2. Polyester
3. Vinyl-ester
4. Urethane
Four Functions of Resin/Matrix - correct answer ✔✔ 1. Transfer stress from fiber to fiber
2. maintain fiber orientation
3. prevent fibers from abrading each other
4. gives environmental resistance (protects)
,Reinforcements - correct answer ✔✔ Material used to strengthen the resin/matrix; at least 50
times stronger and 25-150 times more rigid than the resin/matrix
Main Advantages of Composite Materials - correct answer ✔✔ 1. Increase stiffness, strength, or
dimensional stability
2. Reduce cost
3. Reduce weight
4. Improve design flexibility
Advantages of Composite Materials - correct answer ✔✔ 1. Increase toughness
2. Increase heat-deflection temperature
3. Increase mechanical and sound damping
4. Reduce permeability to gases and liquids
5. Modify electrical properties
6. Decrease water absorption
7. Decrease thermal expansion
8. Increase chemical wear and corrosion resistance
9. Maintain strength/stiffness at high temps. while under strain conditions in corrosive
environments
10. Increase secondary uses and recyclability and reduce negative impact on the environment
Main Disadvantages of Composite Materials - correct answer ✔✔ 1. Labor Intensive
2. Lack of train personnel
3. Inconsistent processing/fabrication
Disadvantages of Composite Materials - correct answer ✔✔ 1. Toxic
2. Required processing
, 3. High tooling cost
4. High cost of equipment
5. Lack of data
6. Underdeveloped inspection techniques
Common types of reinforcement fibers - correct answer ✔✔ 1. Fiberglass
2. Aramid (Kevlar)
3. Carbon/Graphite
4. Boron
Fiberglass Characteristics - correct answer ✔✔ Color: White, Silver, Gray, Translucent
Years: 1940-50's
How is Fiberglass produced? - correct answer ✔✔ Made from small strands of molten glass,
which are then spun together and woven into cloth
Advantages of Fiberglass - correct answer ✔✔ 1. Low cost compared to other types of fibers
2. Availability
3. Good tensile strength
4. Good shear strength
Disadvantages of Fiberglass - correct answer ✔✔ 1. Lower impact strength than other fibers
2. Heavier than other types of fibers
Different Types of Fiberglass - correct answer ✔✔ 1. E-Glass
2. S-Glass
