Determination of Displacement and Strain Fields in Al2O3-FeNi42 Brazed Joints by FEM and Automated Grating Interferometry

The need for strain and stress estimation in ceramic-metal joints requires application of adequate tools that would be able to describe the joint behaviour under applied load precisely. For this purpose we have introduced the automated grating interferometry (GI) method which was used as the high resolution experimental tool to measure the displacement field in brazed Al2O3-FeNi42 joints subjected to four-point bending. The finite element method was applied to verify the results, but also to read the raw data from experimental for further analysis. The measurements and analysis have been narrawed to the C-M interface zone with 3 mm width. The results of displacement distribution from GI and FEM showed good correlation, although the quantitive agreement depends on several conditions, laying both on experimental and numerical sides which are discussed. It is expected that coupling GI with FEM could allow to establish a joint hybrid method od stress estimation by transferring measured raw data into FEM analysis.