What is deformation?
Change of shape when a force is applied
What does the type of deformation depend on
The type of force that is applied to the object
What’s a tensile force
A stretching force
What does a tensile force produce
An extension
How can u calculate extension
New stretched length - original length
What’s the unit of extension
M
What’s a compressive force
A squashing force
What does a compressive force produce
A compression
How can you calculate compression
Original length - new compressed length
What’s the unit for compression
M
How does a shear force act
Force acts across the object
What’s a torsional force
Twisting force
How does a bending force act
Acts at an angle
Elastic deformation
Material returns to its original shape when the force is removed
Plastic deformation
Material does not return to original shape when force is removed
Example of a material that always exhibits elastic behavior
Elastic band
Which materials always exhibits plastic behavior
Plasticene or blue-tak
What’s an example of material that exhibits elastic behavior the plastic behavior before they break
Most metals
What are brittle metals
Materials that exhibit elastic behaviour but then break before any plastic deformation
What happens when a material reaches elastic limit?
Material no longer goes back to original shape
Exhibits plastic behavior
Permanent deformation has occurred
What’s hookes law
The tensile force acting on a metallic object is directly proportional to the extension provided
the elastic limit is not exceeded
Hookes law
F=kx
f is force
K is force constant
X is extension
