Degeneration Effects of Thin-Film Sensors after Critical Load Conditions of Machine Components

Abstract

In the context of intelligent components in industrial applications in the automotive, energy or construction sector, sensor monitoring is crucial for security issues and to avoid long and costly downtimes. This article discusses component-inherent thin-film sensors for this purpose, which, in contrast to conventional sensor technology, can be applied inseparably onto the component’s surface via sputtering, so that a maximum of information about the component’s condition can be generated, especially regarding deformation. This article examines whether the sensors can continue to generate reliable measurement data even after critical component loads have been applied. This extends their field of use concerning plastic deformation behavior. Therefore, any change in sensor properties is necessary for ongoing elastic strain measurements. These novel fundamentals are established for thin-film constantan strain gauges and platinum temperature sensors on steel substrates. In general, a k-factor decrease and an increase in the temperature coefficient of resistance with increasing plastic deformation could be observed until a sensor failure above 0.5 % plastic deformation (constantan) occurred (1.3 % for platinum). Knowing these values makes it possible to continue measuring elastic strains after critical load conditions on a machine component in terms of plastic deformation. Additionally, a method of sensor-data fusion for the clear determination of plastic deformation and temperature change is presented.

Advancements in Monitoring of Tribological Stress in Bearings Using Thin-Film Strain Gauges

“…This value indicates the effective resistance change per cycle and generally describes the compression and elongation of a strain gauge. For the produced strain gauges, the characteristics were determined in previous investigations under tensile loads, and the k-factor was determined to 2.15 [14]. It indicates the proportionality of the resistance change ΔR to the strain ε.…”

A Review on Sensor‐Integrating Machine Elements

“…Under tribological stress in a pin-on-plate tribometer, the resistance change was successfully measured. Taking into account the determined k-factor from previous studies [222] Figure 27. Microscopic image of a produced strain gauge array [221] with permission from SMART2023 Conference.…”

“…Under tribological stress in a pin‐on‐plate tribometer, the resistance change was successfully measured. Taking into account the determined k ‐factor from previous studies [ 222 ] and resistance changes in the range of $$-0.1 \%$$, strains of up to $$60 \, \umu \mathrm{m}$$ m −1 were measured in the sliding contact as a result of a Hertzian pressure of 950 MPa. In the future, the focus will continue to be on the wear behavior within the stressed zone and an integrated temperature sensor.…”

Reliability of Mechatronic Systems and Machine Elements: Testing and Validation

“…In [14], the degradation effects of thin-film sensors are investigated. The investigation includes reliability measurements after high loads, which can occur after the application of a critical component load.…”