FE model evolution of the Main Support Structure interfaces to the ELT Nasmyth Platform from PDR to FDR

This paper offers an in-depth study on the structural analyses, performed in INAF - Observatory of Naples, regarding the Interface Joints installed on the ESO Nasmyth Platform of the MORFEO Main Support Structure (MSS). MORFEO is a first light instrument for the ELT (Extremely Large Telescope) that started, since February 2023, its final design phase. This FE model are validated through FEM Analysis approach, utilizing CAD (Autodesk Inventor) and CAE (Ansys Workbench) software. In order to provide an effective survival validation test, it has been simulated the complete earthquake load condition of the MORFEO MSS with its Interface NP Joints mounted below it and its payloads installed on it. All the useful analyses have been developed in detail. Also the operational conditions of the instrument have been checked, simulating the wind effects and the NP induced distortions. In order to have a lighter model for the MORFEO MSS and shorter computational times, simpler FE models than the 3D CAD have been developed. This discretization is a standard approach in the FEA technique and in this paper it is demonstrated that this method still provides accurate results at global level.