Figure 3.2.

Analytical (solid curves) and finite element (symbols) solutions to the 1-D transient diffusion problem across a contact interface, at four representative time points. Solid circles represent nodal values of the concentration in the range −h/2 ≤ z ≤ 0 and solid squares represent corresponding values in the range 0 ≤ z ≤ h/2. Continuity of the concentration across the contact interface, z = 0, is enforced by the contact interface algorithm. Agreement with the analytical solution serves to further validate the finite element implementation.