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

Abstract

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.

High-Precision Integration of Optical Sensors into Metallic Tubes Using Rotary Swaging: Process Phenomena in Joint Formation

“…In particular, the development of sensory structures and machine elements involves the integration of sensors into mechanical structures. The joint connecting the host structure to the sensor plays a critical role in determining the sensory properties of the resulting sensor structure, including aspects such as sensor linearity and measurement resolution, as discussed in detail in [4].…”

“…Achieving specific pre-load conditions for axial force measurement results in a reduced measuring range for torque measurement and vice versa, as discussed in [13]. This challenge is attributed to the required pre-load conditions for electromechanical sensors, such as strain-gauge-based and piezo-based sensors, as shown in [4].…”

Effect of Heat Treatment on Electrical Insulation of Strain Sensors for Aluminum Cast Parts

“…Recent research towards the integration of sensing elements into metal parts [1,2] opens the possibilities of smart sensing in structural elements that could be produced on a high scale, for example by metal casting [3,4]. In this scenario, the sensor materials should be robust enough to withstand the integration process [4,5] but also the heat treatments, which are usually performed to improve the mechanical properties of metal parts.…”

High-Precision Integration of Optical Sensors into Metallic Tubes Using Rotary Swaging: Process Phenomena in the Joint Formation

“…Joining by forming is becoming increasingly utilized, particularly in applications with precise final geometry [4,5], or for the integration of sensitive sensor elements into metallic structures [6]. Previous works on sensor integration using recess [7] and infeed [8] rotary swaging show the process ability for target-oriented pre-stress conditions.…”