Characterization of Crack Damages in Composite Materials by Using Frequency- and Time-Domain Analysis

Characterization methods for material damage are a critical area of research, as comprehensive detection techniques can significantly enhance safety in production processes. This paper utilizes experimental and numerical methods to explore the relationship between nonlinear coefficients derived from frequency-domain analysis results and crack damages in composite materials. Additionally, it analyzes the time-domain responses of three excitation signals along asymmetric paths under various damage scenarios, revealing distinctive characteristics of damaged materials. Furthermore, it investigates cross-correlation coefficients between different target damages and the damage-free case in the same path direction. Numerical results demonstrate a correlation between the extent of damage and the cross-correlation coefficient. The study also highlights that different excitation signals exhibit varying sensitivities to different damage types. Lastly, a damage index is proposed to quantify the interaction between the propagation path and damage, enabling a more accurate characterization of material damage. This study serves as a valuable complement to existing material damage characterization methods.