In general, the elastic modulus is the measure of an object’s or substance’s resistance to being deformed elastically when stress is applied.
The modulus of elasticity is a specific material constant; it does not theoretically depend on the sample’s geometry.
The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region. A stiffer material will be characterized by a higher elastic modulus.
Definition of the Elastic Modulus
The elastic modulus is defined as
where stress is the force causing the deformation divided by the area to which the force is applied and strain is the ratio of the change in some parameter caused by the deformation to the original value of the parameter. If stress is measured in Pa (pascal), then ‒ since strain is a dimensionless measure ‒ the units of λ will also be in Pa.