The Effect Of Fine Aggregate On The Mass Loss Of High-velocity Projectile And Its Penetration Depth

With the increase of the penetration speed of projectiles, the effects of the fineaggregate in concrete and mortar on the mass loss of projectiles and penetration depthbecome significant, especially when the hardness of aggregate is increased. In previousstudies, the influence of hardness has not been considered carefully and precisely, andtherefore it should be taken into consideration for high-speed penetration. Meanwhile, withthe increase of hardness of the aggregate, the particle size becomes also important to affectthe penetration depth.In this thesis, a series of experiments are implemented for a combination of differentvalues of aggregate and projectile hardness and aggregate size. Different kinds of sand werechosen with several kinds of hardness and particle size for the cast of the mortar targets.Meanwhile, projectiles with four different surface hardness from HRC22to HRC55wereused in each group of test. In theoretic analysis, the interaction between aggregate andprojectile is considered. According to the experiment analysis, the penetration model ismodified with the consideration of hardness and particle size of the sand. The mass loss ofthe projectiles is divided into two parts, melting and the abrasive wear. Both parts arediscussed in the thesis seperately, which leads to an approximate mass loss model ofprojectile in high-speed penetration.