PSI - Issue 40

Aleksandr Zalazinskiy et al. / Procedia Structural Integrity 40 (2022) 461–469 Aleksandr Zalazinskiy at al. / Structural Integrity Procedia 00 (2022) 000 – 000

464 4

 s  (for the plastic deformation temperature of the model material 600 ° C) as follows:

composite

f     

f

f

s   0

s

f

;

m     

m

m   0 s

;

(1)

s

m

where f s , 0 0   are the initial values of the yield strength during stretching of the fiber, matrix, and composite;  – the degree of deformation; f m c f m c , , , , ,       – empirical coefficients. m s

Fig. 1. Dependencies of the intensity of tangential stresses (T) and plasticity ( ( Т σ ); (b) at the deformation temperature of the model material 600 °C. To determine the effective value of the yield strength of the composite, the ratio of mechanics of composite materials was applied (Composite, 1974)   f f sm sf * s         1 , (2) where f  is the volume fraction of fibers (cores) in the deformable billet of an electrotechnical composite. The plasticity diagram (Figure 1b) of the fibers was approximated by the following equation:   k exp f       , (3) where T   k is an indicator of the stress state of the deformable material;  – average normal stress; Т – the intensity of tangential stresses;   , – empirical coefficients. Glass lubricant was used as a medium for creating high hydrostatic pressure on the deformable workpiece, as well as a lubricant (Baque, 1975). The use of such a working medium for HMP is possible when the inner surface of the container is heated to a temperature of 700 ° C. The glass lubrication model is represented by the following dependence: f  ) on the degree of deformation (a) and the stress state index