First, the -direction will be considered. Substituting the strain-displacement equations into the equilibrium equation in the -direction we have
Then substituting these equations into the equilibrium equation in the -direction we have
Using the assumption that and are constant we can rearrange and get:
Following the same procedure for the -direction and -direction we have
These last 3 equations are the steady Navier–Cauchy equations, which can be also expressed in vector notation as (en)