The presented work deals with fast dynamic simulation of non linear joints. An original industrial context illustrates the process, consisting in analyzing, with an eye to prediction, consequences of a stage separation on the Ariane 5 launcher. A pyrotechnic device cuts the structure along a breaking split, which generates a strong shock wave propagating up to the satellites. A two scales approach is proposed to perform an accurate calculation of the joints behavior (place of strong non linearities) within the global simulation of the wave propagation through out the launcher. The numerical tool is widely used, in addition to experimental tests, which are complex and expensive to perform. A method using an experiments and simulations interaction is proposed in order to validate the different numerical approaches.
