Abstract: The dynamic responses of projectile and barrel under the foreign matter obstruction are numerically simulated based on the background of the premature of a certain armor piercer. The mechanism of bore premature is discussed, and the basis and reference are given for fault analysis and zeroing. Two typical forms of foreign matter obstruction are presented: the foreign matter obstruction leads to a sudden decline of projectile velocity or bayonet chamber; and the projectile directly impacts the foreign matter in chamber at high velocity. AUTODYN software is used for numerical calculation of different conditions, the dynamic characteristics of gas flow field, the deformation and rupture shapes of barrel, and the dynamic response of structure and the deformation and rupture of projectile during the high velocity impact are obtained. The results show that the abrupt obstruction and the rapid decrease of velocity in the chamber result in forming the shock wave and local high pressure in the bottom gas. The presence of local high pressure zone can lead to bore premature. The simulated results are consistent with the actual fault condition.The fault repetition test is carried out. Key

Key words: armorpiercingprojectile, foreignmatterobstruction, borepremature, AUTODYNsoftware