RESULTS OF USING VIDEO MEASURING MACHINES IN THE STUDY OF CRACKS IN THE MATERIALS HAVING A LOW REFLECTANCE

Abstract

The feasibility of using video measuring machines for detection and measurement of the defects such as microcracks in the materials (polymers, quartz and organic glasses) of aviation duty is considered. As the aforementioned materials are characterized by low reflectance detection of the microcracks in them is problematic but rather important task because the microcracks present can cause an accident or wandering defect. Threshold (critical) values of the defects which can be revealed by means of such machines of two different models are determined, e.g., the minimal length of the detectable cracks, which can be used as a parameter of the product rejection. Because of the prohibition of carrying out the studies on the real objects we used a technique of provoking defects by indentation. The results of using classical methods (ultrasound, etc.) and data on the defect detection by the developed procedure were compared. The informativeness of the developed methods was increased using the developed techniques, e.g., by contrasting of the microcracks.