Multi-layer compounds with integrated actor-sensor-functionality

A method is presented to integrate the cost and time consuming afterwards-joining technologies of piezo actors and sensors direct in the forming processes for metal blank structures. Possible applications for such parts are vibration/ noise damping, deformable shape control, energy harvesting or several sensor tasks. Different forming processes are experimentally investigated and the limits according to deformation of the brittle piezo components discussed. In the numerical research the piezomodule components (piezo fibre, electrodes and plastics embeddings) are homogenized to create a computation-time reducing simplified material model. In a back-transfer of global loads in the forming simulation a representative volume element (RVE) with cyclic boundary conditions is used to evaluate the loading of the piezoceramic material to describe the function degradation due to forming operation. The comparison of numerically and experimentally determined results in a linear manner lead to the necessarity of further numerical research. The location of maximum piezo-patch loading corresponds well with the numerical investigation. The numerical integral model for function degradation shows a large difference in comparison to the integral experimentally determined values. Therefore extensive experimental research direct on the piezomodule outside the forming compound is planned to fit the degradation model in a nonlinear manner.