Analysis of the Free-Edge Effect in Piezoelectric Laminates under Electromechanical Load by the Scaled Boundary Finite Element Method

• Applicant: Professor Dr.-Ing. Christian Mittelstedt
• Subject Area: Mechanics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 558639335

This research project is dedicated to the investigation of free-edge effects, i.e. the determination of stresses and electric field quantities at free edges in piezoelectric structures and multilayer systems (laminates). In addition to the very basic investigation of such problems, the analytical treatment of these problems is to be addressed using the so-called Scaled Boundary Finite Element Method (SBFEM). At layer interfaces in multilayer systems or laminates, for example at free edges, local stress concentrations occur. In the presence of piezoelectric single layers, concentrations or singularities in the electric field quantities can occur in addition to the mechanical stress concentrations, which is of considerable practical relevance. The investigations are to be carried out with suitable SBFEM formulations, which in the past have proven to be particularly suitable and powerful for the treatment of problems in linear elasticity, this at an extremely low numerical cost. This is particularly important for three-dimensional problems with involved singularities such as the free-edge effect. In this context, the analysis of piezoelectric structures and multilayer systems requires, besides the implementation of the general coupled material law and the extension by the corresponding electrical degrees of freedom, a further development of the SBFEM methodology also with respect to the possible boundary conditions and load cases. In addition to the frequently considered situation of the plane laminated tensile specimen, laminates under bending and torsion will also be considered in the first year of the project. In the second year, the considerations will be extended to cylindrically curved piezoelectric laminates, and finally, in the third year, laminates with piezoelectric layers containing a circular hole will be considered.

• DFG Programme: Research Grants