Avoid Kinks in wire/Par
Young modulus - E = £ units - Pa or Nm-2 • measure diameter of spr
or wire in multiple place
0-stress = HA (A = crag segional I to calculate average diame
E - strain = ¼ for area.
Al-extension • use a longer wire to g
• Amorphus - [glass ] no range order E= FL more accurate measurem
• crystalline - [metals lattice structure, long range order ADL of extension.
• polymeric - [rubber] long chain hydrocarbon molecules Graph Dy_DO • apply more load to app
o grad = DI DE to get a bigger extensio
F
area-energy young modulus ensuring elastic limit i
stored in spring reached.
• Plot a 0/E graph to
W: ½ Foc = ½ kx²
• E meter a value for young mo
Apparatus - ruler • Ensure wine is secure
E measure of stiffness of clamped to prevent slip
the spring • Repeat experiment (load
Hooke's Law clamp table
- The extension of a spring is directly proportional
to the force applied provided the elastic limit is not long wire In ductile m
(load)
reached. pointer mass/ weight Plastic Defo
- occurs due to
in a lattice.
- When a force is
CRACK PROPAGATION Brittle Fracture - Amorphous material dislocations mo
• Brittle materials under tension - Brittle materials are 0 short range/no long range order lattice.
• Lines show how tension links the weak under tension. Brittle - Original bonds
atoms in material - low breaking stress breaking e.g ceramics, cast iron, glass - shape does not
• There is greater amount of stress - snap easily point Follow hookes law removed.
around the crack - Broken brittle materials ab sense of a crystalline structure To strengthen
• Brittle materials break at crack tip can be put back together so no dislocations to produce • add foreign a
making crack bigger and increasing to original structure. plastic deformation to restrict mo
the stress at tip. Leads to crack - Only deform elastically E • Increase amou
propagation resulting in failure. - little/no plastic region. - decrease grain
Ductile material •
A ductile material long range order ↳ all of which
o ↳ can be drawn into wires and movement.
6
shaped easily.
Young modulus - E = £ units - Pa or Nm-2 • measure diameter of spr
or wire in multiple place
0-stress = HA (A = crag segional I to calculate average diame
E - strain = ¼ for area.
Al-extension • use a longer wire to g
• Amorphus - [glass ] no range order E= FL more accurate measurem
• crystalline - [metals lattice structure, long range order ADL of extension.
• polymeric - [rubber] long chain hydrocarbon molecules Graph Dy_DO • apply more load to app
o grad = DI DE to get a bigger extensio
F
area-energy young modulus ensuring elastic limit i
stored in spring reached.
• Plot a 0/E graph to
W: ½ Foc = ½ kx²
• E meter a value for young mo
Apparatus - ruler • Ensure wine is secure
E measure of stiffness of clamped to prevent slip
the spring • Repeat experiment (load
Hooke's Law clamp table
- The extension of a spring is directly proportional
to the force applied provided the elastic limit is not long wire In ductile m
(load)
reached. pointer mass/ weight Plastic Defo
- occurs due to
in a lattice.
- When a force is
CRACK PROPAGATION Brittle Fracture - Amorphous material dislocations mo
• Brittle materials under tension - Brittle materials are 0 short range/no long range order lattice.
• Lines show how tension links the weak under tension. Brittle - Original bonds
atoms in material - low breaking stress breaking e.g ceramics, cast iron, glass - shape does not
• There is greater amount of stress - snap easily point Follow hookes law removed.
around the crack - Broken brittle materials ab sense of a crystalline structure To strengthen
• Brittle materials break at crack tip can be put back together so no dislocations to produce • add foreign a
making crack bigger and increasing to original structure. plastic deformation to restrict mo
the stress at tip. Leads to crack - Only deform elastically E • Increase amou
propagation resulting in failure. - little/no plastic region. - decrease grain
Ductile material •
A ductile material long range order ↳ all of which
o ↳ can be drawn into wires and movement.
6
shaped easily.
