Biharmonic equation
A mathematical function is called biharmonisch in an area, if the so-called biharmonic equation
Satisfied for all points. here is the Laplace operator. The biharmonic equation is thus a partial differential equation of fourth order.
In practice, this equation occurs in the continuum mechanics in drives for example. The deformation of a disk in a first approximation point obeys the inhomogeneous biharmonic equation:
Here, the force ( density) applied to the plate.
Harmonic functions are always biharmonic functions; but the converse does not apply.