Purpose
A resource for educators and researchers interested in the characterization of mechanical material properties from static and dynamic analysis, specifically the modulus of elasticity, E.
The stress-strain relationship contains the material property information that must be evaluated by experiments (laboratory or field), which requires the use of both theoretical and experimental mechanics.
Elastic and Plastic Equilibrium
When to use the theory of elasticity and when to use the theory of plasticity depends on the magnitude of the stresses and/or strains and the deviation of the stress-strain relationship from Hooke's law.
If the stresses and/or strains are large and/or the deviation of the stress-strain relationship from Hooke's law is large then the theory of plasticity should be used.
Both destructive and non-destructive identification (NDI) methods will be explored.
Destructive methods will be used to determine the initial elastic property, the ultimate strength and the fatigue strength.
NDI methods will depend on linear, time independent (LTI) models of materials including visco-elastic models (Kelvin-Voight).
With NDI, experimental stresses and/or strains must be kept within the elastic limit.
How to determine when the experimental stresses and/or strains are outside the elastic limit and/or are non-linear will be explored.