Characterization of innovative CFC/Cu joints by full-field measurements and finite elements

In this study focus is posed on an innovative joint between a Carbon Fiber reinforced carbon-matrix Composite (CFC) and copper (Cu or its alloys) based on the modification of the CFC substrate and on a one-step brazing process with a non-active brazing alloy. To assess the mechanical response of the joint subjected to shear tests, a numerical-experimental methodology is presented herein, which consists of two inverse problems in a sequence, coherently formulated and solved: (i) the "optical" inverse problem tackled by an improved 2D global Digital Image Correlation procedure, allowing one to reconstruct displacement fields from digital images; (ii) the "mechanical" inverse problem, exploiting kinematic full-field measurements and a finite element model to estimate the governing parameters for the joint. The proposed methodology can provide a useful feedback to improve the design process and the validation stage of innovative joining techniques.