Experimental study on the mechanical properties and impact behaviors of entangled metallic wire material under repeated low-velocity impacts

Repeated impacts occur frequently and the damage to its structure cannot be underestimated in national defense weapons and equipment. In this article, the mechanical properties and impact behaviors of entangled metallic wire material (EMWM) with different relative densities under repeated low-velocity impacts were investigated via a series of mechanical tests. Each EMWM specimen was subjected to an impact test of 6 m/s each time, and the test was repeated ten times. Experimental results show that with the increase of the number of impact cycles, the damage of EMWM progressively intensifies, the impact stiffness increases, and the energy absorption rate decreases. The mechanical properties of EMWM with higher relative density are more stable under repeated impacts, it displays stronger repeated impact resistance, and it is suitable to withstand repeated impacts. After reaching a certain number of impact cycles, the energy absorption rate tends to be stable. The energy absorption of the EMWM mainly comes from the dry friction between the adjacent wire helixes, the plastic deformation of EMWM, and air damping. Moreover, the impact failure mechanisms of EMWM under repeated low-velocity impacts were described. The electron microscope photos show that the EMWM specimen has no obvious damage after repeated impacts, and it has good repeatable impact ability.