Impact between fluids and solids. Comparison between analytical and FEA results

Theoretical and numerical analyses of the dynamic force acted on structures by fluid-like debris flows (d.f.) or fluids are presented. Current analyses of the interaction between d.f. and structures usually take into account a modified hydrodynamic pressure or a multiple of the hydrostatic pressure, to determine the impact force. A close examination of analytical and experimental results, mainly pertaining to hydraulic and coastal engineering, regarding the impact of water waves against coastal facilities, however, reveals that these simplified assumptions are not supported by rational presumptions. Numerical (FE) analyses have been therefore carried out and their results compared to the available theoretical and numerical results in the literature. The importance of the impulsive phase of the impact phenomenon, especially if a planar d.f. front face is parallel to the impacted structure, is put into evidence. Proposed FEA results highlight the role of fluid's speed, density and compressibility in the general problem of the impact of fluids against structures.