INITIAL STRESS CORRECTION METHOD FOR THE MODELING OF FOLDED SPACE INFLATABLE STRUCTURES

Abstract

Initial errors and mesh distortions are inevitable in the modelling of folded space inflatable structures. Aimed at this key technical problem, an initial stress correction method based on finite element theory is proposed in this paper. First, initial stress is calculated through the difference of mapping and reference configurations, the former with initial errors and the later without. Then the initial stress is imposed on the mapping configuration to correct initial errors. Through the correction, the accuracy of the inflation deployment numerical calculation is greatly improved. In order to validate the reliability of this correction method, a typical space inflatable structure-inflatable tube is studied as an example. First of all, the finite element models of both Z-folded and rolled tubes are established with the initial stress correction method. Then the inflation deployment numerical calculations of the folded tubes are carried out applying the segmented inflatable control volume method. Through comparative analysis of the calculation results with and without a correction, the method proposed in this paper is proved to be feasible and accurate. The correction method is a complement to the modelling of folded space inflatable structures and it has a great significance for the improvement of the accuracy of the inflation deployment numerical calculations of space inflatable structures.