Stress and Strain Flashcards
What is the formula for Stress?
What is the formula for Strain?
What does this symbol represent?
The stress placed on an object
What does this symbol represent?
The force placed on the object.
What does this symbol represent?
The cross sectional area of the specimen. (m^2)
what does a stress strain diagram look like? Where are the elastic limits, yield point, UTS and failure/ Breaking stress
look at the graph
When the Material is in the Elastic zone, does the material return back to its original shape and size?
Yes.
How would you identify the proportional limit?
The point at the end of the elastic zone, where it meets the start of the plastic zone.
What does this symbol represent?
The strain placed on an object
What does this symbol represent?
The extension of the object. (How much it has changed in length)
What does this symbol represent?
The original length of the object.
What does this stress strain graph represent?
This graph represents an object with High Strength but is brittle. Shown by a straight line that climbs high up the stress axis. Very little strain means low ductility.
This could be a material like glass
What does this stress strain graph represent?
This graph represents a material with high strength yet not brittle. The curled top shows the slightly higher ductility.
This could be a material like a metal alloy.
What does this stress strain graph represent?
This graph represents a material with low strength but high ductility. This is shown through the large amount of strain.
This could be a material like plastic
What does this stress strain graph represent?
This graph represents a material with moderate strength and high strain indicating toughness. Toughness being measured from the area under the curve.
This could be a material like mild steel.
There is a law called hooke’s law, what does this relate to in a graph.
The Linear part of the graph, in materials that contain a linear line at the beginning
Where is the breaking point in a stress strain graph
at the end.
What is Ultimate Tensile strength?
It means the maximum stress an object can take before it can no longer take anymore load.
What is Proof Stress?
Proof stress of a material can be defined as the stress at which the material undergoes plastic deformation.
What is Young’s Modulus?
A measure of the stiffness of a material. It quantifies the ability of a material to resist deformation under an applied force. It is represented by the symbol E and it’s units is in pascals.
how can we see where the Ultimate Tensile Strength on a stress strain graph?
it can be seen at the highest point of the graph.
What is a another unit for Newton meters squared. N/m^2
Pa. Pressure
what is Ductility?
Ductility is how much plastic deformation it will undergo before fracture.
Yield points are?
These points are a marked increase in strain without in an increase in stress.
How is a material determined to be brittle?
if the material does not undergo plastic deformation.
plastic deformation is when a material is stretched and doesn’t go back to shape.
What happens when a material reaches the plastic region
It deforms to point that it will not go back to the original shape or size.
What happens to the material when it reaches the point of necking down on a stress strain graph?
The material undergoes localized deformation where the pressure is being exerted before reaching the breaking point.
What is toughness?
Toughness is a measure of a material’s ability to absorb energy and deform plastically before fracturing. It represents the amount of work required to break a material. Toughness is usually measured by the area under the stress-strain curve of a material up to the point of fracture.
What is resilience?
Resilience is the ability of a material to absorb and store elastic energy when deformed and then release it upon unloading. It is a measure of a material’s capacity to withstand impact or sudden loading without undergoing permanent deformation or fracture.
What is Elastic limit
Elastic Limit is the maximum stress a material can withstand without undergoing permanent deformation. It is the point at which the material reaches its limit of elasticity, meaning it can return to its original shape once the applied stress is removed.
What is work hardening on a stress strain graph?
The section of the graph when the material slips and dislocates, resulting in a strengthening of the material, with a decrease of ductility.
What is uniform extension
That the material is stretching an even amount its length.
What is uniform extension
That the material is stretching an even amount its length.
