Shear creep analysis of solid rocket motor bonding interface and rapid prediction model**

Abstract

During vertical storage of solid rocket motors, shear creep behavior occurred at the sidewall bonding interface due to self‐weight load, threatening the structural safety and storage life of the motor. To study the shear creep characteristics of the bonding interface, shear creep tests were conducted on a shear interface test piece of a motor under various temperatures and stresses. An engineering criterion for the onset of nonlinear viscoelastic stage of the bonding interface was proposed, and a rapid prediction model for shear creep of motor bonding interface in linear viscoelastic stage was devised. Furthermore, the stress‐time master curve of shear creep compliance at the bonding interface was established, revealing the variation trend of shear creep compliance during long‐term creep process. The results showed that this rapid prediction model had simple construction, high accuracy and wide applicability, and could well predict short‐term creep behaviour of bonding interface in linear viscoelastic stage. A method for structural integrity assessment of vertically stored solid rocket motors could be provided by using these research methods and results.