METHOD OF CONSTRUCTING DIAGRAM OF LIMIT DEFORMATIONS OF SHEET MATERIAL Russian patent published in 2016 - IPC G01N3/28 

FIELD: technological processes.

SUBSTANCE: invention relates to stamping, in particular to investigation of mechanical properties of sheet materials for assessment of their ability, as well as for use in CAD/CAE-systems in computer simulation and sheet forming. Invention: on obtained from sheet material sample dividing screen is applied, sample is tested, dividing mesh is measured, minimum main deformation and maximum main deformation are calculated, and diagram of limit deformations is plotted using deformation values applied to coordinate grid on abscissa and on ordinate. Diagram of maximum deformations is built in relative uniform elongation and coefficient of anisotropy of driven certificate on sheet material, by which negative and positive abscissa ordinate of first point on left half of beam of maximum deformations are calculated. Straight line is drawn from first point at angle of 45° to coordinate axes to intersection with ordinate axis at second point, and left half of beam of maximum deformations is obtained. Third point on right half of beam of maximum deformations is built with abscissa and ordinate on condition that when testing sample for two-axis stretching with hemispherical punch or with liquid intensity of deformation of elements near rupture of sample is 2 times higher than intensity of deformations of elements of sample near break during testing on one-axis stretching, known for left half of beam of maximum deformations. Second and third points are connected with straight line, and right half of beam of maximum deformations is obtained.

EFFECT: reduced time and higher quality of design of technological processes and equipment, saving of sheet material, as well as significant simplification of selection of sheet material and equipment for sheet stamping of parts, for example, body parts of cars and other equipment.

1 cl, 2 dwg