Predicting the mechanical behaviour of large composite rocket motor cases

Abstract

A method to develop finite element models of the rocket motor cases of a strategic missile is presented. Based on the use of multivariate analyses, this approach is made necessary given the impossibility to control all input data: difficult characterization of filament wound materials, influence of manufacturing and qualification processes, unknown fabrication parameters, etc. An initial reference model is built up using preliminary data and theoretical winding laws. Having compared the models predictions and available structural test results, a sensitivity analysis is carried out to discuss the individual influence of the input data on the accuracy of the predictions. The multivariate analysis finally enables a global assessment of the parametric analysis results.