Flashcards in Mechanical Properties of Metals - Chapter 8 Deck (15):
Time-dependent elastic strain component -> elastic deformation will continue after the stress application, and upon load release, some finite time is required for complete recovery.
v= Lateral strain/axial strain
Relation between shear and elastic moduli?
E = 2G (1 + v)
The point of yielding may be determined as the initial departure form linearity of the stress-strain curve; this is sometimes called the proportional limit. The strain offset is usually 0.002
It is a measure of the degree of plastic deformation that has been sustained at fracture.
Percentage elongation (%EL)
%EL = [(Lf-Lo)/Lo] x 100
Percent reduction in area (%RA)
%RA = [(Ao-Af)/Ao] x 100
Resilience is the capacity of a material to absorb energy when it is deformed elastically and upon unloading, to have this energy recovered.
Modulus of Resilience (Ur)
Ur = Integration[stress d(strain)]
Assuming a linear elastic region:
Ur = 1/2 (stress)(strain)
Ur = Stress^2/2E
indicates a material's resistance to fracture when a crack is present.
Also indicates the ability of a material to absorb energy and plastically deform before fracturing.