4.2 Solid material Properties Flashcards
what is tension ?
A force acting within a material in a direction that would extend the material.
What is extension?
Increase in size of material caused by tension force.
What is compression ?
Force acting within a material in a direction that would squash the material.
- decrease in size of a material sample under a compressive force.
What is Hookes Law
F = K Δ x
where k is spring constant (Nm^-1)
x is extension (m)
A material only obeys hookes law if it does not pass the limit of proportionality.
What is elastic strain energy?
This is the work done in deforming a material before it reaches its elastic limit.
What is the limit of proportionality?
This is the mnaximum extension than an object can exhibit which is still proportional to the load applied.
What is the elastic limit?
This is a materials maximum extension or compression that the material can undergo and still return to its original dimensions when the force is removed.
What is Hysteresis?
Hysteresis is where the extension under a certain load will be different depending on its history of past loads and extensions.
What is the formula for stress and what are the units?
stress = force / cross sectinoal area
Force (N)
CSA (m^2)
Stress - Pascals , Nm^-2
What is the formula for strain and what are the units?
strain = extension / original length
Extension (m)
original length (m)
strain (No units)
What is the unit of Youngs Modulus?
Pascals
What is the the order in the stress strain analysis?
limit of proportionality
elastic limit
yield point
Ultimate tensile strength
fracture
