基于细观结构的复合固体推进剂含损伤黏弹性本构模型

The macroscopic mechanical properties of composite solid propellant are inseparably linked to its mesoscopic components and damage. A macro and mesoscopic constitutive model of composite solid propellant with void damage was developed based on the evolution of the mesostructure during the deformation process of composite solid propellants. The model takes into account the dependence of propellant temperature and strain rate, and is able to describe the different mechanical responses of propellant in tension and compression. The validity of the constitutive model is verified by tensile and compressive tests at different temperatures and strain rates. The macro and mesoscopic constitutive model is re-developed based on the user material subroutine interface UMAT provided by the finite element software, and applied to the structural integrity analysis of grain under low temperature ignition conditions, indicating that the safety factor of grain under low-temperature ignition conditions is 2. 56, and the structural integrity of grain meets the requirements. Finally, compared with the linear viscoelastic constitutive model based on Prony series, the proposed constitutive model can be used to more accurately analyze the structure of composite solid propellant grains.