TITAN-IV MOTOR FAILURE AND REDESIGN ANALYSES

A fully interactive, gas-flow-grain structural analysis was developed and applied to reconstruct the failure mode of the first prequalificat ion motor and to evaluate the redesigned grain configuration for the T itan IV solid-rocket-motor upgrade. The gas-flow analysis was based on an adaptive, unstructured, finite-element method for the solution of full Navier-Stokes flows inside solid-rocket-motors. The grain structu ral analysis was conducted using a general-purpose, finite-element pro gram with the consideration of viscoelastic properties of the propella nt and orthotropic properties of the graphite-epoxy motor case. The ex act deformed grain geometry was considered in the fully interactive, g as-flow-grain structural analysis. Results of the analyses for the fir st prequalification motor and for the redesign motor agreed well with the data obtained from the static firing tests, The study provided con firmation and confidence required for the implementation of the grain modification. The qualification program for the Titan IV solid-rocket- motor upgrade was completed with five successful tests of the motors w ith the redesigned grain configuration.