Numerical and experimental characterization of CMCs through impulse excitation technique and FEM-based tools

Kurzfassung

Ceramic Matrix Composites (CMC s) are increasingly used in high-temperature and structurally demanding applications because of their low density, thermal stability, and strong damage tolerance. Understanding their elastic behavior is crucial for wider use in industries like aerospace and aeronautics. Researchers have extensively studied the in-plane elastic properties of SiC/SiC composites at room temperature, as shown in Süueß et al. (2024, DOI: ), which examines these properties for possible use in gas turbine guide vanes. However, the out-of-plane elastic behavior is still not well understood. The aim of this internship was to find evaluate the out-of-plane elastic properties of SiC/SiC composites, focusing on Ez, Gxz, and Gyz (x and y: in-plane directions, z: out-of-plane direction). To do this, a mix of numerical and experimental methods was used. Finite Element Method studies in ANSYS helped optimizinge the design of test samples and supported the understanding of the experimental data. After that, samples made from C/C-SiC were tested to confirm the method and ensure consistency when layering SiC/SiC. Experimental identification of eigenfrequencies was performed using the Impulse Excitation Technique, supported by m+p Analyzer software. These frequencies served as the basis for estimating the elastic constants through comparison with the numerical models. The internship produced a validated workflow that can extract out-of-plane elastic properties for CMCs, supporting future design applications in high-temperature aerospace or aeronautics components and improving material characterization. The research results demonstrated that a combined numerical and experimental approach served as a solid basis for determining the out-of-plane properties of C/C-SiC and SiC/SiC, as the numerical iteration closely matched the experimental data.