Application of the Method of Digital Image Processing for Evaluation of Crack Formation of Paint Coatings

Information is given on the application of the method of digital processing of images to assess the cracking of paint coatings. As a paint composition, white water-dispersion paint VA-17 was used. To create a texture, spray paint was applied discretely to the surface of the film. Data processing, calculation of shear fields, volumetric deformations and other additional operations, as well as graphical presentation of the results, were carried out in the MatLab program. The development of a transverse crack, which is the cause of film destruction, was considered. The process of crack formation proceeds from the middle of the film in its narrow part. It has been established that shear bands are observed already at the first stage of loading. It has been established that the appearance of microcracks was detected at a load of 0.01 kgf with transverse strain values of 0.01 mm. As the crack propagates, the isofield of the deformed state of the film changes, the deformations and the fraction of deformation at the crack mouth increase. The application of the digital image processing method will make it possible to develop recommendations for improving the crack resistance of paint and varnish coatings.