HTPB推进剂蠕变本构方程研究

During vertical storage of solid rocket motor, creep deformation of the grain resulting from long-term gravity load lead to the grain sinking to the tail structurally, and disturbing the structural integrity and the interior ballistic performance of SRM. Creep test data of HTPB propellant specimen under stress levels such as 0.4 MPa, 0.5 MPa, 0.6 MPa and 0.7 MPa was used to analyze 12 creep models such as power law model, exponential model and rational model, and the creep constitutive equation applicable to HTPB propellant was determined. The results show that the creep process of HTPB propellant conforms to the general creep law and is described by the power law creep constitutive equation, the combined time hardening creep constitutive equation and the generalized time hardening creep constitutive equation. The fitting results of the combined time hardening creep constitutive equation have the least error with the test data. The fitting curves of power law creep constitutive equations have good consistency with the test curves at all stress levels, which can be used in preliminary analysis or under specific stress levels.