In this paper we develop a mathematical model for the dynamics of a nonlinear Timoshenko beam with piezoelectric actuation. This model can then be used to design controllers with the goal of achieving a desired shape of the beam. The control scheme can be used for several applications, e. g., vibration control in structures or shape control for high-precision structures like inflatable space reflectors. The starting point of the control design is modeling for control. We do this in the framework of port-Hamiltonian (pH) modeling, which has favorable properties, such as passivity and a Hamiltonian representing the energy and serving as a Lyapunov function, that can be exploited for controller design. An important property of the pH modeling ...