Toward Automated Identification And Quantification Of Meso-Scale Damage Modes In Plain Weave Glass/Epoxy Composite Laminates

We investigated three different automated methods for identification and quantification of meso-scale damage on single-layer composite laminates subjected to ballistic impact by a 5.5 mm (0.22 caliber) right circular cylindrical steel projectile. These methods were based on the combined use of high-resolution optical imaging, fluorescence microscopy, and image detection software. High-resolution images of impacted composite samples were processed using either ImageJ alone (method 1, for sample size of 20 x 20 cm(2)) or ImageJ plus MATLAB (method 2, for sample size of 20 x 20 cm(2)), or fluorescence images were processed using ImageJ plus MATLAB (method 3, for sample size of 6 x 5 cm(2)). These methods were used for identification and grouping of horizontal and vertical transverse tow cracks, and 45 degrees matrix cracks. The identified and grouped damage modes were quantified based on spatial pixel count related to damage modes, and quantified damage modes were used to generate a digital damage map using a separate MATLAB code for all three methods. Finally, the advantages and shortcomings of each of these three automated methods for identification and quantification of meso-scale damage modes were evaluated via comparison to a baseline manual method for identifying and quantifying the damage modes on the same samples.