A method has been developed to design a propellant stress relief groov
e (SRG) for solid rocket motors. The method considers a time-dependent
pressure distribution in both burn-back and burn-forward analyses and
allows a desired bondline stress condition to be incorporated into th
e SRG design. Application of the method to obtain an improved propella
nt SRG for the Titan IV solid rocket motor upgrade (SRMU) is illustrat
ed in this paper. The improved propellant SRG obtained from this metho
d for the Titan IV SRMU provides significant enhancement in the propel
lant structural margin of safety throughout motor firing.