Formation of Residual Stresses in Plates with Functional Holes After Mandrelling

Modeling of Cold Plastic Deformation of the Holes Made in Specimens of Shape-Memory Alloy

“…We plotted the distributions of normal residual stresses σ y along the X -axis in the vicinity of the functional hole for the degrees of cold expansion i = 1.5 and 2.4% (Figs. 4a, b) and compared them with the results of FEM evaluation of residual stresses for the plates 60 mm in width with holes of the corresponding diameters [13] for the degrees of cold expansion i = 2 and 3%. We present the plots of residual stresses in the vicinity of the hole for the diameters equal to 8 mm (Figs.…”

“…The distributions of residual stresses in structural elements with holes after their cold pressure treatment can be found by using analytic [7], numerical [8][9][10], and experimental methods [8,11]. The main regularities of the influence of mandrelling tension (degree of cold expansion) and the diameter of the hole on the distribution of stresses in the vicinity of the hole and the durability of plates made of aluminum alloys under loading with constant amplitude were established in [10,12,13]. The holes can be strengthened as a result of cold plastic deformation performed by using various technological procedures: punching of the balls or mandrels of conic shape with calibrating sections [13][14][15] and the methods of split bush [16,17] or barrier drafting.…”