Compact Optical System for Detection of Cracks in Composite Materials

We propose to develop an enhanced digital defect detection system based on laser vibrometry. This system is capable of detecting the defects in composite materials as specified in the solicitation. The instrument will detect and analyze cracks,delaminations and types of flaws critical for composite materials in real-time. The instrument will instantly produce a velocity surface map by measuring the surface displacement at multiple locations. This will produce a map of the oscillation amplitudes,frequencies, and modal patterns from which the strain due to vibratory excitation can be calculated. A robust hand-held tool, insensitive to external mechanical impacts and harsh vibratory conditions, will be produced, including algorithms for dataprocessing. During Phase I, we will develop a model of the proposed single-shot whole-field laser vibrometer, complete a full instrument performance analysis, and demonstrate proof-of-principle experiments of the proposed technology to detect defects incomposite materials. The prototype system will be engineered and built during the Phase II effort. The proposed technique will benefit the military and commercial aircraft industries by enabling real-time inspection of several critical elements incomposite materials. Owing to fast operation and large area coverage, the proposed device will significantly reduce the financial resources required for inspection. It will also offer the possibility of automatic/robotic inspection of the frame structuresmade with composite material by identifying imminent failures. Beyond the aerospace and automotive industry, the device will be useful for many other applications, including the inspection of civil infrastructures such as roads and bridges, and for noisesource analysis in the automobile industry. Other areas include landmine detection and civil engineering applications for visualizing the effects of shock waves (earthquakes, bombs, etc.) on large-scale structures after a shock wave impact. The method canbe used in any application where it is necessary to record,