Numerical analysis of high density alloys and elongated projectiles’ velocity and strength effect on their penetration into a steel target

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Fig. 6. Change of parameters during the steel target penetration of the VNZh-90
alloy rod with the yield strength of 1000MPa at the initial interaction velocity of
2000m/s
Both the projectile trailing end velocity ve and the steel target contact
boundary velocity vc of a low strength projectile remain constant during
the whole penetration process. Their values drop to zero only at the very
moment when the projectile length reduces to the value close to its diameter
(see Fig. 5, a). On the contrary, in the case of a high-strength projectile
there is a visible reduction of the velocities ve and v c at the early stages
of the process (see Fig. 5, b). This fact correlates with the Alekseyevsky –
Tate rod-shaped projectile penetration model [4, 5]. Velocity reduction of
the remaining part of the high-strength projectile during the penetration
results in reducing contact stresses σ zc while contacting with the target (see
Fig. 5, b). For a low-strength projectile these stresses remain approximately
constant up to the moment when the projectile length becomes zero
(see Fig. 5, a). The performed analysis highlights physical factors, which
cause a higher penetration effect when a projectile with the yield strength
σY = 50 MPa is used comparing to a projectile with the yield strength
σY = 1500 MPa at the interaction velocity v0 = 1400 m/s.
78 ISSN 0236-3941. HERALD of the BMSTU Series “Mechanical Engineering”. 2015. No. 1