Application of measurement nets for deformation evaluation at bending

Abstract

The article points out various ways of applying measurement nets on the steel sheet specimens. Advantages and disadvantages of the main deposition procedures and its practical use are shortly described. Also the shape of measurement nets pattern is discussed. In this paper the measurement nets were applied for determination of plastic deformation in the bending zone of sheet specimen. In that purpose on selected sheet specimens with different coating layers net pattern in shape of circles were etched by electrochemical method. Bending is performed using a special bend jig. After bending the bent samples were measured by an optical device. Measurements included the thickness of the bent sheet samples and the dimensions of the individual circles after deformation. Based on measurement results the logarithmic deformation φ1, φ2 and, φ3 are then calculated.