A novel procedure to determine the effects of debonding on case exposure of solid rocket motors

Solid rocket motors are complex systems which need to withstand extreme physical conditions in terms of temperature, pressure, and high-density energy release. Therefore, specific attention should be brought to the flaws that may occur during motor manufacturing\handling phases prior to launch. An example of such flaws is debonding, usually arising at the interface between case insulation and solid grain. When debonding is significant in size, it may result in the premature case exposure to combustion chamber hot gases, and, in worst cases, it may even cause a complete motor failure. This work is intended to evaluate the impact of propellant debonding on solid rocket motor case-insulating layer, making predictions about the most unfavorable regions where the debonding could occur. Numerical simulations are performed with an in-house simulation software applied to an actual solid rocket motor stage.