Study on acoustic emission parameter fusion-based NOL ring damage assessment method for modeling hydrogen storage cylinder shells

Abstract

In this study, we examined the damage progression in the NOL ring of fiber-reinforced composites during axial failure, utilizing an acoustic emission methodology. The NOL ring is used to simulate the destruction process of the fiber-woven material of the shell of a hydrogen storage cylinder during pressurization. We constructed three combined eigenvalues (AERA, AER, and AEb) derived from the parameters of acoustic emission amplitude, energy, and rise time to characterize and evaluate the damage status of the NOL rings. In the first instance, we analyzed NOL ring specimens at varying tensile stages using AERA values, discovering that these values could delineate the tensile damage of the NOL ring into three distinct phases. Following this, we employed the AERA and AER values to substantiate the demarcation of the NOL ring damage phases. Additionally, we analyzed the AEb values using the consistent load-bearing segment at different junctures of the cyclic loading experiment to confirm the validity of the AE parameter fusion. The findings indicated that the AERA and AER values were highly responsive to the early damage and the cumulative damage changes in the specimens. In the third phase of NOL ring extension, the AERA values displayed a high degree of variability and complexity. On the other hand, the AEb values declined rapidly beyond 0.85Fmax. This evidence corroborated the appropriateness of the three fused characteristic values—AERA, AER, and AEb —in evaluating the NOL ring damage progression.