Creep-Induced Stress in Solid Rocket Motor Bonding Interfaces During Cooling and Long-Term Vertical Storage

Abstract

With the increasing complexity of military missions, silo launch has emerged as a prevalent deployment method for solid missile systems. Long-term vertical storage of solid rocket motors (SRMs) leads to creep deformation in the propellant due to gravitational forces, particularly affecting the bonding interface of Nitrate Ester Plasticized Polyether (NEPE) high-energy solid propellants. This paper employs finite element analysis (FEA) using ABAQUS software to evaluate the stress state of the bonding interface during 180 days of vertical storage, with a specific focus on curing and cooling conditions. The results highlight significant stress concentrations at the root of the insulation layer's stress release, which could potentially lead to fracture propagation. Additionally, the study finds that the bonding interface experiences a complex stress distribution, including tensile and shear stresses, which are particularly evident near artificial debonding roots.