浇注炸药PBX-1侵彻安定性试验与数值模拟

为了研究浇注型高聚物黏结炸药(PBX?1)在侵彻过程中的安定性,开展155 mm火炮发射平头试验弹侵彻混凝土靶板试验,获得了该试验条件下装药安定的临界侵彻速度约为490 m·s^-1。基于黏弹性统计裂纹(Visco?SCRAM)模型,采用流固耦合方法模拟了安定性试验中装药的力学响应,计算了装药黏弹性变形和宏观裂纹损伤导致的温升。数值模拟结果与试验结果相一致,试验弹弹体侵彻后无明显的变形和破坏,但浇注PBX炸药在侵彻过载下发生大变形流动,部分装药从尾部缝隙挤出并发生了局部点火反应;侵彻过程中装药尾部会与药室底部发生高速碰撞,形成局部高压区,最高压力超过500 MPa,装药尾部变形和损伤严重,装药尾部在碰撞和挤出时,温度会急剧升高,从而导致意外点火。

Experiments and NumericalSimulations of Penetration Stability of Cast Charge PBX-1

To study the stability of a cast polymer?bonded explosive(PBX)during penetration,projectiles with the PBX?1 charge was launched by a 155mm gun to penetrate concrete targets.The penetration depths at different velocities were obtained,and the critical penetration velocity for maintaining the charge stability was about 490 m·s-1.Based on the viscoelastic statistical crack(Visco?SCRAM)model,the experiments for testing penetration stability were modelled by a fluid?solid coupling method with large deformation.Thermal?mechanical responses of the charge during penetration were obtained and reasons for the unexpected ignition of the charge were analyzed.The numerical results and experimental data are in a good agreement.The results show that no obvious deformation or damage is observed for the projectile shell,while the cast PBX charge undergoes large deformation and part of charge seeps out from the end gap.During the penetration process,the charge collides with the bottom of charge chamber at high speed and forms a local high?pressure zone.The maximum pressure exceeds 500 MPa when the charge tail is impacted.The tail of the charge is deformed and damaged severely,which may lead to a highly localized temperature and even ignition.