Materials Flashcards
What is Hooke’s Law
Force is proportional to extension, up to the LIMIT OF PROPORTIONALITY
What is the limit of proportionality
If exceeded, there is no longer a linear relationship between force and extension
What happens after the Elastic Limit
The sample will no longer return to its original shape when the force ceases to be present
What is the Yield Point
The force will become so great that the material snaps
What is tensile stress
The stress applied to a material is the force per unit area applied to the material
What is tensile strain
The ratio of extension to original length is called strain
What is elastic strain energy
This value can be determined by calculating the area under the the force-extension graph
What is breaking stress
The maximum stress a material can stand before it breaks
How to find Young’s Modulus
Tensile Stress/Tensile Strain
What is the spring constant for two springs in parallel
K(total) = K(1) + K(2)
What is the spring constant for two springs in series
1/K(total) = 1/K(1) + 1/K(2)
What is the extension of two springs in parallel
Extension is half the amount of the extension of each spring (assuming both springs are the same)
What is the extension of two springs in series
Extension is double the amount of extension of each spring (assuming both springs are the same)
Describe the stress-strain graph for a ductile material
Median elastic region, then a very long plastic region, so it can be stretched into wires
Describe the stress-strain graph for a plastic material
Extremely short elastic region, long plastic region
