Setting Discrete Yield-stress Sensors for Recording Early Component Loading Using Eddy-current Array Technology and Induction Thermography

Abstract

Problematic requirements, regarding the assessment of the integrity of highly loaded components require that modern methods be developed to record the component's loading history during its life cycle. New developments are moving towards a continuous monitoring of loading history using sensors as well as towards determing the material's or component's state during its service. This requires integrating the load sensors into the component in order to record the component's loading online. Based on the physical material properties of metastable austenitic steels, a novel design is developed for implementing local, component-inherent load sensors; so-called directionally-sensitive yield-stress sensors. The appropriate strengths and yield stresses, corresponding to the component loading to be monitored, can be specifically set by locally heat treating the selected, cold-worked sensor's region using a fibre-laser. Electromagnetic testing methods, such as eddy current technology and imaging induction thermography are developed to rapidly collect the technical data of such microstructures which possess modified physical material properties. The measuring technology is developed and adapted to the testing task via modelling. FEM computation are also performed both for describing the domain's scope and the eddy current distribution, as well as for simulating the magnetising processes as well as the chronological formation of temperature fields in the component's edge region.