FEM analysis on the “self-sharpening” behavior of tungsten fiber/metallic glass matrix composite long rod

Abstract

In the present manuscript the geometrical model of tungsten fiber/metallic glass matrix (WF/MG) composite long rod is established based on the microstructure of composite, and a modified coupled thermo-mechanical constitutive model is employed to describe the high strength and high shear sensitivity of metallic glass (MG) matrix. Then the finite element method (FEM) simulations on the penetration of WF/MG composite long rod into the steel targets are conducted by integrating with related penetrating tests. The effects of impact velocity, target strength and initial shape of rod nose on the “self-sharpening” property of rod and the consequent penetrating performance are discussed in detail. Corresponding analysis shows that due to the high shear sensitivity of MG matrix, a significant “self-sharpening” behavior occurs in the composite rod, and the rod nose maintains as a sharp shape during the penetration. Comparatively, for the tungsten heavy alloy (WHA) rod, the nose blunts as a “mushroom” shape due to the relatively high plasticity of material. The “self-sharpening” behavior leads to a relatively lower resistance for the rod, and thus the composite rod achieves a much better penetrating performance compared with the WHA one. Moreover, the impact velocity and the target strength play an important role for the “self-sharpening” property and the consequent penetrating performance of the WF/MG composite long rod, whereas the initial nose shape has a relatively slight effect.