Development of new finite element models to predict the dynamic behavior of shells subjected to flowing fluids

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Shell structures constitute critical components in aerospace and aircraft engineering, nuclear power plants and naval structures. The aforementioned industries generally use thin-walled shells under high rates of fluid flow and require low shell thicknesses. Under these conditions, the structure becomes very susceptible to instability and failure. The objectives of the proposed work is to develop more sophisticated finite element models that have a larger scope than the existing ones. This permits modeling of more realistic cases while ensuring their reliability. This work is a part of our long-term objective that consists to complete our finite element models based on a reliable and very accurate approach at lower cost relative to experimental method. The first topic is to extend our existing axisymmetric hybrid model to study truncated conical shells subjected to a random boundary layer induced by internal turbulent flow. This requires obtaining the cross-correlation spectral density of the fluid and the mean square value of the displacements of the shell for an arbitrary pressure field and for a boundary-layer pressure. The case of plates and shells subjected to supersonic flow is also an important issue to deal with in the present research project. This allows simulating curved and panels like aircraft fins or turbine blades subjected to supersonic flow. The third research subject concerns the integration of the hyperelastic behaviour of the solid shell when interacting with a fluid. In this research, strain-invariant constitutive models will be used to describe the behaviour of hyperelastic materials. The latter makes it possible to apply our finite element models to structures with more realistic material properties. The last theme concerns the reformulation of the hybrid axisymmetric model coupled with a compressible internal flowing fluid. The objective is to resolve the issue related to fluid boundary conditions imposed on the inlet and outlet of the structure. The development of new numerical models and the improvement of existing ones are motivated by the fact that existing software in this field covers only very limited cases of fluid-structure interaction. In addition, our interest to develop annular flow models is an important opportunity to extend our expertise to others applications. All these developments and their results will be useful to international scientific community working on vibrations of structures in interaction with flowing fluid. Practically, the majority of all the research projects supported by NSERC are also have had and will have the supports of the industry. For instance, the new ALLIANCE program (Industry-NSERC) created by NSERC and replacing the former programs (RD-Coop and Engage). The applicant has and had every three or four years a project of RD-Coop and/or Engage (Bombardier, PWC, Hydro Quebec, CAE, etc.).