A simple demonstration of nonlocality in a heterogeneous material is presented. By
analysis of the microscale deformation of a two-component layered medium, it is
shown that nonlocal interactions necessarily appear in a homogenized model of the
system. Explicit expressions for the nonlocal forces are determined. The way
these nonlocal forces appear in various nonlocal elasticity theories is derived.
The length scales that emerge involve the constituent material properties as
well as their geometrical dimensions. A peridynamic material model for the
smoothed displacement field is derived. It is demonstrated by comparison with
experimental data that the incorporation of nonlocality in modeling improves the
prediction of the stress concentration in an open-hole tension test on a composite
plate.
