UC San Diego

Despite a high strength to weight ratio, composites are susceptible to impact damage which can be barely visible while still adversely affecting their strength, therefore detecting and characterizing damage is important. Non-destructive evaluation, specifically single-sided pulse-echo ultrasonic C-scans, can be used to detect damage. The goal is to develop a code that aids the quantitative assessment of damage within laminates by segmenting C-scans of damaged regions into 3D reconstructions. The code is open source to create a free alternative to commercial ultrasonic C-scan software and allow users to adapt the code for their own applications. The code processes C-scans and calculates time-of-flight (TOF), then uses unique characteristics in C-scans to create a map of boundaries where the damage changes from one layer to another. Using this map, the code processes the TOF to create a 3D reconstruction of damaged layers. When both front and back side C-scans of a sample are available, the code combines them to produce a hybrid C-scan that merges information from both. The code is developed using a dataset of 25-ply composite panels with varying layups and levels of impact damage. A 24-ply composite sample impacted at 48 Joules was also processed and compared with an X-ray CT dataset. The code's 3D reconstruction output is useful for an enhanced understanding of the impact damage state (e.g., area of damage at specific depth), provides the capability to extract quantitative metrics of the damage, and can be used to create actual-geometry structural analysis model representations of the damage state.