The axisymmetric problem is considered, while the punch speed was set to
CAD/CAE DEFORM-3D. Matrix was set to zero speed. The punch and the matrix
were considered absolutely rigid.
To describe the mechanical properties of blank materials adopted elastic-plastic
material model. The hardening curves were specified in a table in CAD / CAE
DEFORM-3D system for processing temperatures. Mechanical properties were also
set for blank materials: for aluminum alloy, the modulus of elasticity Е = 0,7110
5
MPa,
poisson ratio = 0,34, and titanium alloy the modulus of elasticity Е = 1,1210
5
МPа,
poisson ratio = 0,32.
Analysis of the results of the displacement force calculation (fig. 5) showed that
with a minimum coefficient of friction =0,01 (fig. 5, а) the maximum values of the
deformation forces do not differ significantly. By increasing the friction forces between
the matrix and the workpiece to
.
=0,3 (Fig. 5, b) there is an increase in the drawing
force with a decrease in the angle of the working part of the matrix. So when drawing
through a matrix with an angle = 4 the force on the punch is 47% more than the
draw force through the matrix with an angle = 10. This is due to the increase in the
working surface area of the matrix at = 4. With an increase in the coefficient of
friction also increases the work of drawing the blank, which is determined by the area
of the corresponding graphs in fig. 5.
а
б
Figure 5. The graph of force dependence on the movement of the blank
system, aluminum-titanium, at: a –
.
=0,01; b –
.
= 0,3; 1 - = 4°; 2 - = 7°; 3 -
= 10°
Distribution of radial compression stresses (Fig. 6) on the boundary surface is
characterized by a gradual increase in proportion to the degree of compression. The
maximum compressive stresses correspond to the zone close to the output of the matrix.
In this case, their value increases with decreasing angle and reducing the coefficient
of friction.
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