USE OF CORROSION PRODUCT FOR DIGITAL IMAGE CORRELATION MEASUREMENTS

This paper describes the results of work performed to assess the use of corrosion product for Digital Image Correlation (DIC) measurements. DIC was recently evaluated for its capability to measure contour, strain and deflection of metals using the corrosion product instead of a painted speckle pattern. The DIC system, consisting of two cameras with zoom lenses, was set up at an angle to the specimen, enabling both cameras to image multiple sides of a specimen simultaneously. This provides a more direct measurement of in-plane and out-of-plane deformation and strains. Aluminum and steel dogbones were placed in a salt spray chamber for up to 10 days. Contour measurements were then taken at various evaluation settings as an initial assessment of the use of the corrosion product for DIC measurements. Multiple tensile tests were then performed to assess the capability of using corrosion product for strain and deflection measurements while a material is under applied load. System bias and deviation was determined using static images taken of the corroded dogbones. Test results and analysis are presented in detail in this paper, as well as conclusions drawn as a result of these tests.