Random Material's Characteristics to Study Fluid‐Structure Interaction

Summary In many situations, the vibrating structures are in contact with a fluid (fluid around the hulls of a boat, reservoirs, heat exchangers in power plants, etc.), but the dynamic behavior of the structure can be significantly modified by the presence of the fluid. The sizing must take into account the effects of fluid-structure interaction. Traditionally, the study of mechanical systems fluid-structure interaction is based on a deterministic approach where all the parameters used in the model are a fixed value. But it suffices to having conducted a few experimentations to realize that the limitations of such modeling. Hence it needs to take into accounts the uncertainty in the parameters of mechanical systems. This work proposes to take the characteristics of the structure and the fluid as random and shows the efficiency of such approach. The proposed numerical stochastic method of the modal synthesis extended to reliability study, based on FORM (First Order Reliability Method) and SORM (Second Order Reliability Method) approaches, for solving the large vibro-acoustic problems. The numerical method used takes into account the uncertainties of the input parameters of the two domains. The application of the proposed method is performed on a boat propeller immersed in air and water. To validate the calculation process, the numerical study is compared to an experimental study.