Damage evaluation and failure behavior of clamping plates assessed by non-destructive evaluation

초록

Composite-based fastening systems exhibit complex failure behavior due to the material anisotropy and geometric configuration. The structural response is governed by the combined effects of curvature-induced deformation and stress concentration at the hole region, which were experimentally evaluated through controlled loading tests, indicating the limitations of simple strength-based assessments. A multi sensor based monitoring approach incorporating acoustic emission (AE), electrical resistance (ER), and sound level (dB) measurements was employed to capture real-time damage evolution during mechanical loading. Additional localized tests were performed on the curved and hole regions to separately evaluate damage initiation and propagation. Thermal shock tests were conducted to evaluate the effects of environmental degradation. The results revealed a dual damage progression, with delamination growth in the curved region and stress concentration induced fracture in the hole region, as confirmed by load-displacement response and sensor signal variations. Cumulative AE activity and ER variation consistently reflected interfacial debonding and disruption of conductive pathways. Thermal shock caused a slight reduction in maximum load, while increasing the sensitivity of damage detection. The proposed multi-sensor-based approach enables systematic evaluation of damage evolution and provides a practical framework for assessing structural response and material degradation in composite fastening systems.

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