ACOUSTIC-WAVE PROPAGATION ALONG PIPELINE NETWORKS

In order to understand the shocks mechanisms propagation, the CERT / O NERA / DERMES is interested in structural waves propagation in piping system network. The free vibration of a cylindrical thin-walled shell can be described by the Donnell-Mushtari theory, added to Flugge formu lation. The resolution of this equations system leads to a 6 order equ ation in omega (motion frequency). In this way, we obtain the axial, r adial and circumferential propagation modes eigenfrequencies. However, due to the hypothesis of long pipe assumption, only the radial mode i s taken into account. The theoretical approach is completed by an expe rimental study. Thus, the waves propagation along straight pipes and i n complex system (in 3-D) including some representative discontinuitie s of system network (single 45-degrees bend, single 90-degrees bend, T -Joint, curved-pipe...) is analyzed. The aim is to quantify the amplit ude attenuation of a radial propagation mode of the shell through thes e kind of discontinuities. The study is carried out in order to realiz e a numerical simulation software of vibrational waves propagation alo ng piping system network. This study is financed by a natural gas tran smission company : Gaz du Sud-Ouest.