측면하중 예측을 위한 발사체 엔진 노즐 3차원 고정밀 구조해석 개발

Abstract

In this thesis, an advanced structural analysis is proposed and developed for the prediction of launch vehicle engine nozzle sideward loads. Specifically, the present analysis considers the regenerative cooling channel. The specific elements used are the shell element, which combines the optimal triangle membrane element and discrete Kirchhoff triangle plate bending element. The laminated composite material is considered by improving the existing formulation of the relevant stress-strain relationship. Equivalent structural modeling is conducted considering the outer/inner surfaces and cooling channel of an engine nozzle. The accuracy and efficiency of the shell element are validated by examining both modal and time-transient analyses. The present equivalent structural modeling procedure shows sufficient accuracy when compared with the prediction that takes account of the original solid element assemblage by considering all the detailed three-dimensional components. To consider the thermal stress in the engine nozzle, the thermomechanical analysis of the engine nozzle is conducted. By conducting the fluid-structure interaction analysis based on the present structural modeling, accurate predictions for launch vehicle engine sideward loads will be anticipated.