Quantitative Assessment of Fiber Fracture in Damaged Laminates Using X-Ray Radiography
Abstract
In this paper, a new technique for extracting quantitative information about fiber fracture from dye penetrant enhanced X-ray radiographs is described. In this new inspection method, the observer marks fiber fracture zones on a digitized version of the radiograph depicting the damage state. Image processing routines are used to isolate the marked fiber fracture zones, and then extract fiber fracture parameters such as the length of the longest fiber fracture zone and the total length of fiber fracture from the marked image. The technique has been used to quantify fiber fracture in graphite epoxy laminates damaged by either quasi-static contact loading or low-velocity impact. The residual strengths of these specimens were found to correlate well with the fiber fracture parameters, with specimens containing more fiber fracture exhibiting lower residual strength.