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Recently, composite materials/structures are getting increasingly used in the automotive and aerospace industry. Defects issue is commonly associated with the use of composite materials/structures. Reliable Non-Destructive Evaluation (NDE) of composite structures is still challenging due to the existence of small size defects. In this research, a hybrid approach is used to accurately determine small size internal defects. In this hybrid approach, X-Ray Computed Tomography is used as a reference to accurately determine all defect locations, then a digital shearography method is used to conduct fast NDE for in-line testing. The critical shearographic NDE parameters such as shearing angle, shearing distance and loading amount are determined and optimized based on the X-ray CT scan result. From the comparison of X-ray CT scan results and digital shearography NDE results, the detection rate of digital shearography for defects with a size of larger than 1mm is from 91.91% to 97.30%.

In response to the need for lightweight design in industries, composite materials are increasingly used to replace traditional metal tubes. However, subsurface defects such as voids, delaminations, and microcracks are still remaining common issues in composite pressure tubes. This paper introduces an application of Digital Shearography method in the Non-Destructive Testing (NDT) of high-pressure composite tubes. A new prototype high-pressure composite tube with a working pressure of 1000 psi range is tested using the digital Shearography method. To detect the sub-surface defects, a reference Shearographic phase map is created at 0 psi state, after that the composite tube is pressured using an oil pump, then the second Shearographic phase map is created at the pressured state. By subtracting the two shearographic phase maps created in different pressure state, the sub-surface defects can be identified clearly. The Shearographic NDT result is then compared with CT scan result.