考虑螺栓断裂的固体导弹水平跌落安全性分析

目的通过数值仿真分析水平跌落条件下的固体导弹安全性。方法基于LS-DYNA进行全弹水平跌落仿真计算,通过位移和加速度的实验测量值进行模型校核。重点分析螺栓断裂对结果的影响,对比螺栓在不同建模方法、不同断裂数量下的仿真结果。基于经过校核的全弹模型,计算含能材料的应力场。结果不同建模方法中,螺栓连接法的加速度峰值计算精度最高;不同工况之中,三部段工况下的螺栓断裂数量与实际一致,且加速度峰值计算精度最高。根据精度最高的仿真模型计算出的全弹应力响应,战斗部与发动机装药内部最大Von Mises应力均小于反应阈值。结论螺栓连接的建模方法和断裂数量对于全弹位移、加速度的计算精度具有显著影响。采用螺栓连接法建模的三部段工况仿真模型最为可靠。基于可靠模型的含能材料应力场计算结果表明,全弹6 m水平跌落不会直接引起战斗部、发动机装药反应。

Assessment of Solid Fuel Missile Safety in Horizontal Drop Test Involving Bolt Failure

The solid fuel missile safety in horizental drop test was assessed through numerical simulation. The 6m drop test of solid fuel missile with main axis at horizontal orientaion was simulated using LS-DYNA. The numerical model was verified with displacement and acceleration test data. Stress field was calculated based on the verified model to indicate whether energetic metarials would be ignited. Results from different bolt joint model and different quantities of bolt with failure were compared. It demonstrates that the bolt connection method has the highest accuracy when calculating the peak acceleration among all the modeling methods; the 3-segment condition generates the the most accurate quantity of bolt with failure and peak acceleration numerical solution. According to the most accurate numerical model, the maximum Von Mises stress inside the warhead and engine are both less than the reaction threshold. In conclusion, it is found that the modeling method and quantity of bolt with failure have a significant effect on the calculation accuracy of displacement and acceleration. The most reliable simulation results are obtained by the 3-segment condition and using the bolt connection method for modeling. The stress field result based on the most accurate numerical model indicates that a 6-meter horizontal drop of the entire missile will not directly cause the ignition reaction in the warhead and engine.