Numerical Modeling of the Thermo‐Mechanical and Electrical Behavior of a Sensor‐Integrating Jaw Coupling

ABSTRACT Industry 4.0 requires more and more data from the production process, for example, on transmitted forces, torques and wear, in order to reduce expensive downtimes and to increase productivity. Direct or indirect methods can be used to collect this data. For direct measurement, the sensors can be integrated directly into the load‐bearing machine elements, thus creating a sensor‐integrating machine element. In order to investigate the effect of design choices on the performance of (i) the machine element or (ii) the sensors it is advantageous to create a numerical model for such a sensor‐integrated machine element. In the current work a sensor‐integrating jaw coupling, with which the torque can be measured via dielectric elastomer sensors (DESs), is investigated. The sensors are located in the individual teeth of the gear rim of the coupling. They change their capacitance when they are deformed. This is used to predict the torque. The gear rim of the jaw coupling is made of thermoplastic polyurethane (TPU), which has viscoelastic and temperature‐dependent properties. In order to be able to take these temperature‐dependent properties into account, an existing finite element model, in which a mechanical‐electrical model is implemented, is extended by the thermal field. Due to its use as a sensor, it has been shown that a one‐way coupling between the mechanical and electrical field is sufficient. With the proposed model, the heating of the gear rim due to loads with high frequencies and the effect of this heating on the capacitance change is analyzed. The numerical simulations have shown that the heating is concentrated at the tip of the gear rim tooth.