PSI - Issue 40

Aleksey Antimonov et al. / Procedia Structural Integrity 40 (2022) 17–26 Aleksey Antimonov, Nadezhda Pushkareva / Structural Integrity Procedia 00 (2019) 000 – 000

21 5

Let’s use this formula to estimate the productivity of the rolling breakage process. Then the equation (3) to determine the number of cycles to fracture will be as follows:

1 0,26

1 1 ln 1 16 



.

(4)

N



      

The deformation range will be defined as the relative deformation while bending the balk by Pisarenko, Jakovlev and Matveev (1988) y    , (5) where y − is the distance from the neutral line (axis) of the balk to some point in the cross section,  − the radius of the neutral line curvature. Suppose that the neutral line is a part of the circle and  = const. We define the radius of the curvature through the deflection h at the end of the rolling and the length l which protrudes beyond point B, i.e. the tool (Fig. 6).

Figure 5. Comparison of calculated results by the formula (3) with the experimental data:

Figure 6. To determining the curvature radius.

1 and 4 - experiment, 2 and 3 – calculations. Pipes sizes, mm: 1 and 2 – 9,6x2,95,  = 60; 3 and 4 - 13x3,32,  = 40.

Let the point O of the center of the neutral line curvature be located on the continuation of the line BC. Then from the equality of the side AC of triangles ABC and AOC we obtain

2

2 l

.

(6)

 

h

/ 2 y D  .

The maximum deformation occurs on the outer surface when

In this case

2 Dh l

.

(7)

 