Macro-meso models for joint submitted to pyrotechnic shock

摘要

The work presented deals with the propagation of pyrotechnical shocks in complex structures and, more specifically, through joints between the stages of the Ariane 5 space launcher. As it is a failure cause for satellite equipment, the National Center for Spatial Studies (CNES) is interested in predicting the hardness levels of the shock. A computational difficulty appears near joints as phenomena deeply depend on fine geometrical and mechanical details that cannot be taken into account in the whole structure model. To carry out the calculation, a two scales strategy is used: a structure scale where the joint appears as a nonlinear interface between shells, depending on a few parameters, and a mesoscopic scale dedicated to the joint where each detail and local physical phenomena can be integrated. Moreover, an appropriate and efficient strategy is used to take these two scales into account, identify the macro-model parameters and make it reliable. Each scale computation is described and first results are commented.