Chapter 12 - Technical Engineering Flashcards
What is a component?
Is a part that performs a mechanical function
What is linking?
The mechanical function performed by any component that connects different parts of a technical object
What are the characteristics of links? /4(8)
Direct/ Indirect
Rigid/ Flexible
Removable/ Non-removable
Complete/ Partial
What is a direct link?
When two parts hold together without a linking component
Ex. Tire and wheel of a bicycle
What is an indirect link?
When the parts REQUIRE a linking component to hold them together.
Ex. Door and hinge (need a screw)
What is a rigid link?
When the linking component or the surfaces of the linked parts can NOT be deformed
Ex. Knife blade and handle
What is a flexible link? /2
When the linking component or surfaces of the linked parts can be deformed.
Can be subject to constraints
Ex. Springs, rubber
What is a removable link? /2
Linked parts can be separated WITHOUT DAMAGE on either their surfaces or the link itself (if present)
Ex. Nails, screws, bolts (MUST BE PRESENT)
What is a non-removable link?
Separating the linked parts DAMAGES their surface or the link (if present)
Ex. Brick wall (cement and brick will break if taken apart)
What is a complete link?
Linked parts can NOT move independently of one another
Ex. Shovel
What is a partial link?
AT LEAST ONE part can move independently of the other parts
Ex. Wheel of a skateboard
What are the different types of constraints? /5
Compression Tension Torsion Deflection Shearing
What is a constraint?
Describes the effect of external forces in a material
What kind of constraint is compression?
Subjected to forces that tend crush
Ex. Crushing a can
What kind of constraint is tension?
Subjected to forces that tend to stretch
Ex. Copper stretched into a wire
What kind of constraint is torsion?
Subjected to a force that tends to twist
Ex. Wringing a wet towel
What kind of constraint is deflection?
Subjected to forces that tend to bend
Ex. Clothes weighing a clothes line
What kind of constraint is shearing?
Subjected to forces that tend to cut
Ex. Scissors cutting paper
What is deformation?
Extended forces on materials and that have a tendency to deform them
What are different types of deformation?
Elastic
Plastic
Fracture
What kind of deformation is elastic? /2
Temporary change in shape or dimensions of the material
When the constraint applied is removed, the material returns to its original form
Ex. Spring, sponge
What kind of deformation is plastic? /2
Permanent change in the shape or dimensions of the material
Even when the constraint is removed, the material stays deformed
Ex. Scrunching of paper
What kind of deformation is fracture?
The constraint is so intense that the material BREAKS
Ex. Glass
What is degradation of a material?
The decline in some of its properties due to the effects of the surrounding environment
What is the protection of a material?
The application of procedures that prevent or delay it’s degradation
What are mechanical properties of materials?
Describes how material reacts when subjected to constraints
What are the different properties of materials? /7
Hardness Elasticity Resilience Stiffness Toughness Ductility Malleability
What kind of property is hardness? /3
Ability to resist indentation or abrasion (dents and scratches)
High: concrete, diamonds
Low: wax, play-doh
What kind of property is elasticity? /3
Ability to return to its original shape after undergoing a constraint
High: skin, elastic, balloon
Low: most things that are not rubber (to an extent)
What kind of property is resilience?
Ability to resist shocks without breaking
High: car bumper
Low: glass
What kind of property is stiffness?
Ability to retain its shape when subject to constraints
What kind of property is toughness?
Ability to absorb energy
Ex. Black panther‘s suit
What kind of property is ductility? /4
Ability to be stretched without breaking
Shape materials
Manufacturing materials
Do not describe the function of metals
What are other properties of metals? /6
Chemical neutrality
Resistance to corrosion
Electrical conductivity
Heat resistance
Thermal conductivity
Lightness
What kind of property is chemical neutrality?
The material does NOT react with other substances
Ex. Science desks
What kind of property is resistance to corrosion?
Ability to resist the effects of corrosive substances which cause the formation of rust
Ex. Hubcaps protect tires
What kind of property is electrical conductivity?
Ability to carry an electric current
Ex. Metals, wires
What kind of property is heat resistance?
Ability to resist heat
Ex. Ceramics
What kind of property is thermal conductivity?
Ability to transmit false
What kind of property is lightness?
Not heavy, nor dense
