MATEPRO Module 5 Flashcards
4 Roles of Materials in the History of Man
- Association of dominant material to time periods: Stone Age, Bronze Age, Iron Age
- Similar to manufacturing, it determines what is possible and contributes to comfort, productivity, safety and security of everyday living.
- One replaces another when new advantages and capabilities are
realized. - Knowledge of material properties is essential to an engineer in
manufacturing: Structure, Properties, Processing, Performance.
Iron, copper, aluminum, magnesium, nickel, titanium, lead, tin, and zinc are what type of material?
Metallic materials
wood, rick, concrete, glass, rubber, and plastics are what type of material?
Nonmetallic materials
______, such as fiber glass are capable of
demonstrating higher strength at a LOWER WEIGHT and VOLUME.
Composites
used to distinguish one material from another: weight, density, melting point, optical characteristics, thermal and electrical properties, etc.
Physical Properties
describe how a material responds to applied loads or forces: tensile strength, yield strength, Modulus of Elasticity,
etc.
Mechanical Properties
force per unit area experienced by a material: S = F/A
Stress
stress that causes material to increase in length (+deformation)
Tensile Stress
stress that causes material to reduce in length (-deformation)
Compressive Stress
the amount of deformation divided by the material’s original length: e = ΔL/L
Strain
observed when the applied loads are constant (not changing)
Static Properties
observed when the applied loads are changing: impact loads, fluctuating loads, time-dependent effects, etc.
Dynamic Properties
- Measures the behaviour of
a material with respect to a
tensile load - Uses the Universal Testing
Machine (UTM)
Uni-Axial Tensile Strength
- Proportional Limit (Hooke’s Law)
- Young’s Modulus (Modulus of
Elasticity) – ratio of stress to strain;
measure of toughness - Elastic Limit
- Resilience
- Modulus of Resilience
- Plastic Deformation
- Yield Point
- Offset Yield Strength
- Ultimate Tensile Strength
- Necking
- Breaking Strength / Fracture Strength
The Engineering Stress-Strain Curve
is the behavior when the load is first applied, the specimen elongates in
proportion to the load. The specimen returns to its original length and shape if the load is removed.
Linear elastic
occurs when the yield stress of the material
is reached.
Permanent (plastic) deformation
is defined as the ratio of the applied load, P, to the original cross-sectional area, Ao, of the specimen:
𝜎 = P/Ao
Engineering Stress (Nominal Stress)
e = (l-lo)/lo
Engineering Strain
As the specimen begins to elongate under a continuously increasing load, its cross-sectional area decreases ________ and _____________ throughout its gage length.
permanently, uniformly
If the specimen is __________ from a stress level higher than the yield stress, the curve follows a _______________ and _________ to the original slope of the curve.
unloaded, straight line downward, parallel
the maximum engineering stress of the material.
Tensile strength or ultimate tensile strength (UTS)
If the specimen is loaded beyond its ultimate tensile strength, it begins to ____, or ____ down
neck, neck
the engineering stress at fracture
Breaking or fracture
- the ratio of stress to strain in the elastic region.
- the stiffness of the material
E = 𝜎/e (Hooke’s law)
Modulus of Elasticity (E) or Young’s modulus
