Smart metal sheets by direct functional integration of piezoceramic fibers in microformed structures

2022

Prod. Eng. Res. Devel.

In recent years, the trend to extend the functionality of passive metallic structures in mechanical engineering through sensor integration has emerged. This trend is driven by the growing demand for monitoring and/or control approaches. Current state of the art sensory structures and machine elements are successfully produced by integrating sensors into metallic structures using various joining techniques. However, the widespread implementation of sensory structures and machine elements has a long way to go to be achieved. For this purpose, the sensory structures must be produced not only as standardized components, but also cost-effectively with flexible configuration of the sensory characteristics and the integration of associated electronics. This paper provides an overview of the latest joining technologies for sensory structures. A discussion of the features of each joining technique will be given. In view of the importance of force/torque measurement in load-bearing structures and machine elements, an overview will be provided on the advantages and challenges of joining processes that substitute electromechanical transducers with optical non-contact measurement techniques.

Section: Pressingmentioning

confidence: 99%

Sensor-integrated structures in mechanical engineering: challenges and opportunities for mechanical joining processes

2022

Prod. Eng. Res. Devel.

“…Schubert et al introduce the integration of micro-piezo modules in micro-structured cavities within the surface of an aluminum sheet, prior to generating a force fit [12] and a form and force fit joint [13] by pressing.…”

Section: Motivationmentioning

confidence: 99%

In-process calibration of smart structures produced by incremental forming

Krech

2020

Prod. Eng. Res. Devel.

Smart load-bearing structures are created by forming integration of functional materials into passive metallic components with target-oriented pre-stress conditions by rotary swaging. Their sensory capability cannot only be used during the utilization but also during the manufacturing phase. Previous works demonstrated how this capability paves the way for efficient monitoring and controlling of the used integration process. In search of an even higher overall efficiency of the manufacturing chain, the subsequent costly calibration step deserves closer attention. Therefore, a cost- and time-efficient approach for the process-integrated calibration of a sensor-integrated structure is proposed in this paper. During the in-process calibration, the acting process forces are measured both in the integrated sensor and in a special-built clamping fixture. The measured data can be transferred into calibration slopes of the sensory structures. A suitable signal processing based on the process characteristics is performed to compensate interference effects on the raw signals. As a result, an accuracy of the calibration better than 2% of the nominal value compared to an offline standardized calibration is achieved with the in-line calibration method. Consequently, efficiency in the manufacturing of sensory structures is further boosted by avoidance of setup or logistical operations.

International Journal of Smart and Nano Materials

“…The same also applies for the concept of the structural integration of piezoceramic material in lightweight construction without the use of any elastic interlayers. The technological feasibility of the individual process steps for the production of so-called piezo-metal modules has already been proven [1]. The manufacturing principle is based on the micro assembly of piezoceramic fibers into local microstructured aluminum sheets, with subsequent joining by forming.…”

Section: Introductionmentioning

confidence: 99%

Monitoring concept for structural integration of PZT-fiber arrays in metal sheets: a numerical and experimental study

Drossel

Schubert

Pütz

et al. 2018

The technique joining by forming allows the structural integration of piezoceramic fibers into locally microstructured metal sheets without any elastic interlayers. A high-volume production of the joining partners causes in statistical deviations from the nominal dimensions. A numerical simulation on geometric process sensitivity shows that the deviations have a high significant influence on the resulting fiber stresses after the joining by forming operation and demonstrate the necessity of a monitoring concept. On this basis, the electromechanical behavior of piezoceramic array transducers is investigated experimentally before, during and after the joining process. The piezoceramic array transducer consists of an arrangement of five electrical interconnected piezoceramic fibers. The findings show that the impedance spectrum depends on the fiber stresses and can be used for in-process monitoring during the joining process. Based on the impedance values the preload state of the interconnected piezoceramic fibers can be specifically controlled and a fiber overload.