摘要 |
Material defects and damage are detected and evaluated by stressing the material and looking for flaw-induced anomalies in a fringe pattern generated by the interference between two coherent laser beams and electronic image processing. In terms of apparatus, the system includes a sensor head and a head-mounted display (HMD) interfaced to a computer, power supply, and control electronics. In one embodiment, the sensor head contains a thermal stressing unit and an in-plane displacement sensitive ESPI arrangement which measures the in-plane displacement of the deformation induced by applying thermal stressing. In operation, a thermal stressing unit is integrated with the sensor head to provide a slight temperature difference between a localized region and surrounding areas, with the change in temperature being used to reveal the defects and damage through the interference between the two laser beams and electronic image processing.
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