High-fidelity numerical simulation and experimental validation of a 1600-mm-diameter axial loaded grid stiffened cylindrical shell

Abstract

Stiffened cylindrical shells are commonly used in the launch vehicle, which are prone to buckling under axial compression load and extremely sensitive to imperfections. Establishing a high-fidelity finite element model is a prerequisite for correctly analyzing buckling load and imperfection sensitivity of stiffened cylindrical shells. This paper proposes a homogenization-based model updating approach for the grid stiffened cylindrical shell with many chamfers, which can establish a high-fidelity shell finite element model that maintains calculation efficiency and accuracy advantages. It uses the equivalent elastic constants of the unit cell as the link to modify the size parameters of the finite element model for the grid stiffened cylindrical shell. Moreover, the axially compressed buckling test of a 1.6-m-diameter orthogrid stiffened cylindrical shell is performed to verify the effectiveness of the proposed method. Through comparison, it could be found that the updated finite element model has a higher analysis accuracy. Specifically, the analysis error of the initial finite element model is −16.85% compared with the test result, while the error of the updated model is only −0.67%. The updated model can be used with full confidence for simulating mechanical performance such as the buckling process and the imperfection sensitivity analysis. Besides, it also indicates the necessity of considering the structural characteristics such as the chamfer in the optimization design process of the grid stiffened cylindrical shell structure.