Topic 4 - pt.1 Flashcards
(41 cards)
list the mechanical properties
- tensile and compressive strength
- stiffness
- toughness
- ductility
- elasticity
- plasticity
- Young’s Modulus
- stress
- strain
list the aesthetic characteristics
- taste
- smell
- appearance
- texture
list the properties of smart materials
- piezo electricity
- shape memory
- photocromocity
- magneto-rheostatic
- electro-rheostatic
- thermoelectricity
electrical resistivity
a material’s ability to conduct or resist electricity
thermal conductivity
a measure of how fast heat moves through the material
thermal expansion
the degree to which a material increases in its dimensions due to heat
hardness
the resistance of a material to scratching or penetration
tensile strength
ability of a material to withstand pulling forces
- important for selecting materials for ropes and cables
compressive strength
ability of a material to withstand being pushed or squashed
- important for selecting materials for structures e.g. pillars
stiffness
the resistance of an elastic body to deflection by an applied force
toughness
the ability of a material to plastically deform without fracturing –> a material’s resistance to fracture when stressed
plasticity
ability of a material to be changed in shape permanently by external blows or pressure without cracking or breaking
stress
the force per unit area of a material
- normally determined by applying a tensile force to material
strain
after a tensile force is applied to a material it’s expected to be elongated
Young’s Modulus
measure of stiffness of an elastic material –> ratio of stress along an axis to the strain
photo-chromocity
material that can be described as having a reversible change of colour when exposed to light
thermoelectricity
generated by a device that converts heat and the temp difference between materials into electricity
magneto-rheostatic
fluids which can experience a dramatic change in consistency when exposed to a magnetic or electric field
- e.g. thick fluid to solid really quickly
piezo electricity
squeeze or pressure giving off a small electrical discharge
shape memory
metals that have a rearrangement of the molecules in the material due to changes in temp
composite materials
materials made from two or more materials with different physical or chemical properties –> when combined produce a material w different characteristics from original
- this is done to make materials stronger, lighter, or less expensive
advantages of composite materials
- high strength to weight ratio
- high tensile strength
- when weaving it can produce a prettier look
- (weaving) different materials can be chosen to make it more strong or stiff
disadvantage of composites
- very expensive
- requires specific manufacturing facilities
- weak when compressed or squashed
- air bubbles will cause weak spots and reduce overall impact
- difficult or can’t be recycled
plywood
- manufactured from an uneven number of plys
- needed where high quality, high strength, and large sheet material is required
- resistant to cracking, breaking, shrinkage, and twisting
- can be used as an engineering material for architecture or marine environments