发动机装填蜂巢状药型安全力学特性研究

Research on the Safety Mechanical Properties of Beehive Propellant Grain in SRM

蜂巢状装药由于其药型结构复杂,难以通过实验准确获得其点火过程中力学特性。为准确反映大推力蜂巢装药推进剂在点火过程中对药柱破坏情况,对大推力蜂巢药柱进行装药结构完整性分析,采用含累积损伤的非线性粘弹性本构模型,利用ABAQUS有限元软件二次开发的UMAT子程序,分析研究了蜂巢状装药在点火过程中的安全力学响应,同时分析了蜂巢状药柱六边形内孔几何参数和星尖倒角半径对装药结构完整性的影响规律。结果表明:药柱内孔六边形边长和星尖倒角半径对应力影响很大,边长越小药柱应力越小,圆角半径越大药柱应力集中现象减弱,且随着装药内外压差的增大应力响应越大。研究结果可对蜂巢装药内孔边长和倒角半径等结构参数的设计起到参考作用。

Due to the complexity of charge structure, it is difficult to obtain the accurate mechanical properties of Beehive propellant grain under ignition pressurization loading. To develop the structure integrity analysis of the high - thrust beehive propellant under ignition pressurization loading, the numerical simulation was implemented by using the secondary developed UMAT subroutine of the ABAQUS finite element software of the beehive propellant, under the differential pressure of the interior and the exterior, in which accumulative damage nonlinear viscoelastic constitu- tive model was employed. The influences of loading characteristic, grain geometric parameter and fillet radius on grain＇s structure integrity were analyzed. The results show that the maximum stress can greatly decrease accompanying with the decreasing of edge length. The effect of star tip fillet radius on grain＇s stress centralization weakens and the grain structure integrity is strongly affected by pressure difference value. So the suitable grain edge length and fillet radius should be chose to solve the issue of the beehive propellant under ignition pressurization loading, which has reference value to grain design.