Structural efficiency evaluation of innovative reusable launch vehicles

Abstract

This work is focused on evaluating the structural design of the innovative reusable micro launcher MESO, originated from the RRTB, a funded project by EU. The structural efficiency of MESO is evaluated in association with its mass budget, which is based on project’s early adopted requirements. In this particular design loop, the reusability concept is intergraded by implementing the fail-safe design approach, considering the exclusive use of high TRL aluminum alloys. The main objective of this work is achieved by developing a global Finite Element Model (FEM), comprising a set of sub-models, which represent the primary structure, the secondary structures, the equipment and their interfaces as well.The paper proceeds with the description of the modelling approach regarding mesh development and the connections created between the sub-models for assembling the integrated Global FEM of the launcher. The first iteration of the load analysis loop resulted in the extraction of the Design Limit Loads (DLL). The DLL investigated in both ground and flight cases, which comprise the most severe combination of quasi-static loads. The FEM is verified and subjected to various types of preliminary structural analysis, taking into consideration the required ECSS design and safety factors for static strength and stability assessment.The analyses results indicated the order of magnitude and the location of all weak areas of the launcher. Subsequently a preliminary sizing procedure is performed in order to prevent all failure modes according to the structural design requirements. The conclusions derived from the structural analysis of the first design loop influence the design modifications to be considered for the next design loop, where the same steps are going to be followed until the structural design requirements are satisfied once again.