Toward automated identification and quantification of meso-scale damage modes in plain weave glass/epoxy composite laminates

Abstract

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 × 20 cm2) or ImageJ plus MATLAB (method 2, for sample size of 20 × 20 cm2), or fluorescence images were processed using ImageJ plus MATLAB (method 3, for sample size of 6 × 5 cm2). These methods were used for identification and grouping of horizontal and vertical transverse tow cracks, and 45° 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.

Numerical study on the effects of oblique impact on the ballistic behavior of 3D angle interlock woven fabric

“…We utilized the ImageJ program (Kumar et al., 2021) to accurately measure the area of damage resulting from impact in the numerical simulations. This image process software can analyze front-view images of the 3DAWF after penetration and calculate the precise amount of colored, damaged area visible in each image (Bonyi et al., 2020). By using this method, we were able to quantify the extent of the damage caused by each impact.…”

Automated detection and quantification of transverse cracks on woven composites

“…Although this work investigated single-layer composites, it may be extended to multilayer composite surface investigations using fluorescence techniques investigated in previous work. 23 Capture One DB 9.1.2 software was used with the Phase One IQ180 to capture RAW images ( Ã .IIQ format). The full resolution of the captured images of the 3 × 3 in 2 (76 × 76 mm 2 ) specimens is 8205 × 7760 pixels with a spatial resolution of 300 dots per inch.…”

“…The six specimens were impacted at velocities ranging from 166 m/s to 439 m/s. 23 The wide range of impact velocities resulted in a large variation in quantities of all damage types. This previous work began with a baseline method in which highresolution images of the ROI were examined, subdivided into 40 × 40 unit cells, and the cracks in each unit cell were manually counted.…”

“…These manual counts were then compared to an automated method that used ImageJ 24 and MATLAB (The MathWorks, Inc.) to process the images and extract the data. 23 A third method was investigated using fluorophore dyes to illuminate cracks, but it required destructively reducing specimen size to an ROI of 2 × 2.4 in 2 (50 × 60 cm 2 ) to fit into a fluorescence imager as well as a series of washes to remove excess fluorophore to achieve optimal crack detection. Hence, a nondestructive study comparing specimens of equal size and similar amounts of a single damage mode was needed to further develop and evaluate the performance of automated methods for identifying and quantifying transverse cracks.…”