5 - Material and component considerations Flashcards
(27 cards)
Compressive strength
Define the material property and give examples
The ability to withstand being crushed or shortened by pushing forces (compression). E.g. surface of a seat when sat on, multi-story car park
Steel, glass, ceramics
Tensile strength
Define the material property and give examples
The ability to resist stretching or pulling forces (tension). E.g. suspension bridge cables & climbing ropes, screws
e.g. high speed steel, tungsten, titanium, CFRP, kevlar, nickel-based superalloys
Stiffness
Define the material property and give examples
The ability to resist forces that may bend a material. E.g. shelf between two supports, deck of a bridge
Hardness
Define the material property and give examples
The ability to resist abrasive wear such as scratching, surface indentation or cutting. E.g. drill bits
E.g. carbon fibre, graphene, titanium, fibre glass, kevlar
Durability
Define the material property and give examples
Ability to withstand wear, damage and weathering.
e.g. outdoor equipment
most metals, ABS, HIPS
Biodegradable
Define the material property and give examples
The ability of a material to break down naturally and decompose by the action of microorganisms. E.g. polylactic acid (PLA), wood
Impact resistance / Toughness
Define the material property and give examples
Ability to absorb impact force/ shock loading without fracture
Eg. ABS, PC, metals
Plasticity
Define the material property and give examples
Ability to be permanently deformed (shaped) and retain the deformed shape
PPS, NEEK, Nylon
Elasticity
Define the material property and give examples
Ability to be deformed then return to original shape once force removed.
E.g. Elasticated cuffs in clothing, rubber, nylon
Malleability
Define the material property and give examples
Ability to withstand deformation by compression without cracking. Increases with temperature. E.g. hammering a metal under heat
aluminum, iron, copper, bronze
Ductility
Define the material property and give examples
Ability to be drawn out under tension, reducing cross-sectional area without cracking. E.g. stretching a material into a wire.
Copper, Alluminium, steel, brass
Corrosion/ degradation resistance
Define the material property and give examples
The ability of a material to withstand environmental attack and decay. E.g. lampost
Stainless steel, allumnium, polypropylene
Density
Define the material property and give examples
The mass of a material in a standard volume of space
Density = Mass / Volume
Strength-to-weight-ratio
Define the material property and give examples
Comparing the weight of the structure to the amount of the weight it can support without failing. E.g. titanium, alluminium, HDPE have high strength-to-weight ratios.
Flammability
Define the material property and give examples
How a materials burns once ignited and the degree of difficulty required to cause combustion.
e.g. cooking pots should not be flammable
Thermal conductivity
Define the material property and give examples
- Thermal conductor: allows the transfer of heat energy through the material.
- Thermal insulator: prevents the transfer or heat through the material
- Note: cooking pans should be conductors, but the handles insulators.
Electrical conductivity
Define the material property and give examples
Electrical conductor: allows the flow of electrical current through the material. Gives very little resistance to the flow of charge
Electrical insulator: does not allow the flow of electrical current through the material.
Define physical material properties
Charicteristics related to the make-ip or structure of a material, which can be observed without changing the material, such as density, magnetism, corrosion resistance and conductivity.
Define mechanical material properties
Properties related to how a material responds to an external fource, for example toughness, ductility, hardness, malleability, compressive strength.
Desribe ergonomics
Ergonomics – interaction between people and the products they use. Reduce stress, improve comfort, increase efficiency
Ergonomic Factors
Product weight
Layout of controls – and user interface
Describe anthropometrics
Anthropometrics – measurements of the human body – e.g arm length, grip strength and range of motions.
Data grouped based on factors like age, gender, nationality
Data tables normally used 5th, 50th and 95th measurements
Define smart materials
OCR smart materials definition: materials with one or more properties (e.g. mechanical, thermal, optical, or electromagnetic properties) that can be varied in a predictable or controllable way in response to external stimuli, such as, for example, stress, temperature, moisture. e.g. shape memory alloys, motion control gels
SHE STOMPSS
Give 10 smart materials
- Shape memory alloys
- Hydrophobic materials
- Electrochromic materials
- Shape memory polymer (polymorph)
- Thermochromic pigments
- Oleophobic
- Motion control gels
- Photochromic pigments
- Self-healing polymer
- Self-healing concrete
Name 4 hardwoods
Oak, birch, teak beach
