Abstract: Focusing on the multi-slice winding composite laminate′ thickness measurement, a fast thickness measurement method based on industrial CT technology was proposed. Based on the characteristics of the CT image of annular component section, at first the circle center of the annular component was quickly determined by using two strings. Then, the boundary of different materials in industrial CT image was determined by half-height method. Finally, the thickness of composite material along radius direction is calculated according to the gray curve variation. A double-layer annular contrast standard sample was tested, the thickness measurement of the standard sample was realized by using the proposed method of this paper, and the results were compared with the three-coordinate system′s measurement results. The comparisons proved that the proposed method of this paper can realize the rapid measurement of arbitrary layer thickness of multi-layer annular composite components, and the maximum relative error is less than 1% for the measurement of annular contrast standard sample thickness.

Key words: composite material, thickness measurement, industrial CT, half-height method