Global to local FEA validation for complex geometries: submodeling technique applied to mechanical structures for ELT class of instrumentation

The following paper illustrates the submodeling technique applied to mechanical structures, that can be considered a tradeoff between the burdensome, under a computational point of view, fully 3D models and the simpler defeatured model obtained from lines and surfaces. This approach allows to have results that are compliant to the actual behaviour of the real object and on the other hand a quick response by the calculation and analysis software. The case study refers to a main support structure of an optical instrument, and focuses in particular on the central joint between the main parts composing the full structure. The way to model truss-shaped structure is investigated both from a geometric point of view and with boundary conditions. The nomenclature and materials mostly refer to the ANSYS Workbench (R) software.