Experimental testing of pre-stressed granular assemblies as a surrogate material for the dynamic analysis of launcher cryogenic tanks

Abstract

This paper focuses on the experimental validation of a new methodology for substitution of Liquid Hydrogen (LH2) on a simplified model of launcher cryogenic tank in vibration analysis by using pre-stressed grains as surrogate materials. The objective of the experiments presented here is to analyze the modal behavior of the (Tank and Granular materials) system during pre-stress procedure. In these experimental tests, a cylindrical tank is fully filled with granular materials and vibrated under swept sine and random excitations. Then, the natural frequency of each vibration mode is measured at different levels of pre-stress. The results obtained from the tests show the evolution of each flexural mode as a function of applied pre- stress. Nonlinear behavior of the analyzed system during vibration was also observed. These experimental values carried out with Tank-Granular material system (TGM) are compared with numerical and analytical results to prove the potential of the new methodology. Finally, based on obtained experimental results, some solutions are proposed in order to improve the new methodology for vibration analysis of cryogenic tank which is an important thematic in aerospace engineering.