PENETRATION EXPERIMENTS FOR NORMAL IMPACT INTO GRANITE TARGETS WITH HIGH-STRENGTH STEEL PROJECTILE
高强钢弹对花岗岩正侵彻的实验研究

A series of normal penetration experiments into granite targets with high strength steel projectiles are conducted using light gas gun. The diameter of projectiles is 15 and 20 mm. The final depth of penetration versus striking velocity is acquired,and a new empirical penetration equation is established accordingly. the final depth of penetration predictions from the new penetration equation is identical with experiments. As indicated by experiments,when the striking velocity is about 900 m/s,the projectile is bent. Target dimension effect of scale-model experiments is analyzed. For obtaining availability data,the maxima dimension of projectile must be restricted for a fixed dimension target. The dynamic strength of granite target is estimated,which is many times larger than the unconfined compressive strength. The rigid-body average deceleration is estimated using the law of conversation of energy,and it is in good agreement with numerical results. Static penetration experiment with high-strength steel projectile also is conducted,and the depth of static penetration is very small. It indicates that the stress wave stirred by striking is very important for penetrating.