7. Non Metallic NDE, Acoustic Microscopy
An analytical and experimental study is conducted to determine criticality of interlaminar disbands by NDE methods. Criticality of such flaws in a shear environment (action of shear near support) is defined in terms of crack propagation and is analyzed by principles and methods of fracture mechanics. Growth of disbands under cyclic loading is also being studied. Fajlure under compressive loading in presence of a disband is defined in terms of buckling and an elastic stability analysis is utilized for assessing criticality. Analytical predictions are compared with experimental results in both cases.
Chatterjee, S. N.; Hashin, Z.; and Pipes, R. B., "Nondestructive Evaluation of Flaw Criticality in Graphite-Epoxy Laminates" (1980). Proceedings of the DARPA/AFML Review of Progress in Quantitative NDE, July 1978–September 1979. 33.