by Hans-Christoph Grunau, Guido Sweers.

**Series:** 2013-10, Preprints

- MSC:
- 35J40 Boundary value problems for higher-order elliptic equations
- 35B50 Maximum principles

**Abstract:**

It is known that the Dirichlet bilaplace boundary value problem, which is

used as a model for a clamped plate, is not sign preserving on general

domains. It is also known that the corresponding first eigenfunction may

change sign. In this note we will show that even a constant right hand side

may result in a sign-changing solution.

**Keywords:**

clamped plate equation, uniform load, sign changing solution