Evaluation of Actuator, Sensor, and Fatigue Performance of Piezo-Metal-Composites

Fabrication technologies for multilayer-composites with sensor and actuator functionality were proposed in a previous study. Inside the compounds, macro-fiber-composites (MFCs) are embedded in a layer of epoxy adhesive between two outer aluminum sheets. Forming takes place while the adhesive is still in an uncured state. Relative displacements between the layers and the MFC is possible, which reduces friction loads for the brittle piezoceramic fibers of the MFC. This paper deals with the experimental and numerical characterization of the actuator and sensor functionality dependent on different bending radii and additionally the fatigue behavior of the compounds. The sensor functionality is tested with a shaker, which initiates a defined deflection. The electric response of the integrated MFC is measured and simulated by use of an analytical sensor function model based on strain components. The actuator performance, measured with a distance laser sensor, is modeled with a voltage-temperature-analogy and compared with values from the experiment. The fatigue behavior and the performance reduction of embedded MFC are investigated with cyclic four-point-bending loading. Loads near and above the elastic limit of the sheet metals cause a higher delamination tendency. Specimens that are loaded at a reasonable distance from the elastic limit reach the high cycle fatigue limit of 2.0E + 06 cycles. Thus, the production method for multilayer-composites with embedded piezoceramic fiber modules discussed in this paper is suitable for the manufacturing of structural parts that undergo a high number of load cycles.