Applications of Digital Image Processing in Testing and Evaluation of CompositeMaterials

摘要

This report describes the development and application of digital image processingtechniques for analyzing the fracture behavior and environmental deterioration of test specimens prepared from composite laminate materials used in the manufacture of helicopter rotor blades. The digitized images were evaluated using pixel histograms generated through routines developed on a C-interpreter. Laminate fiber orientation and aging conditions were found to have a significant effect on the observed fracture patterns and surface characteristics of the test specimens. Pixel histograms of environmentally aged test specimens were broader and shifted to higher grey level values compared to histograms of the unaged specimens. Under the test procedures developed, digital image analysis results were reproducible and fiber orientation did not significantly affect the average grey level of either aged or unaged specimens. Keywords: Digital image analysis, Materials evaluation, Composites, Helicopter blades, Environmental durability, Vision system, Mechanical testing, Nondestructive testing. (JES)