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为研究某型NEPE推进剂药柱受温度、内压及过载等载荷联合作用下的结构完整性,基于近似不可压三维热粘弹性有限元法,建立了发动机药柱的三维有限元计算模型。针对NEPE推进剂的力学特性,采用最大应变能准则给出了不同工作温度下药柱结构的安全系数,讨论了松弛模量与泊松比两种材料参数对药柱结构完整性的影响。结果表明,工作温度较高时药柱结构的安全系数较低,适当降低推进剂的松弛模量或增大泊松比可提高药柱结构的完整性。
In order to study the structural integrity of a type of NEPE propellant grains under the combined action of temperature, internal pressure and overload, a three-dimensional finite element model of the engine grain was established based on the approximate three-dimensional incompressible viscoelastic finite element method. In view of the mechanical properties of NEPE propellants, the maximum strain energy criterion is used to give the safety coefficient of the column structure at different operating temperatures. The effect of relaxation modulus and Poisson’s ratio on the structural integrity of the column is discussed. The results show that when the working temperature is high, the safety coefficient of the column structure is low. Proper lowering of the relaxation modulus of the propellant or increasing the Poisson’s ratio can improve the integrity of the column structure.